!check.def version 241008 =========(Note: year month day encoding) ==========
# check.def contains the tests, error thresholds, short warning messages
#   and text offering some explanation and advise issued by 
#      the program PLATON when run in the 'VALIDATION' mode 
#   
#           This file is read when PLATON is called with the '-u' switch
#                    (e.g. 'platon -u sk1500.cif')  
#   
# - Validation output will be in the order as defined implicitly below, 
#   subject to being split-up in ALERT A, B, C & G section  
#   
# - Tests are identified with three-digit numbers   
#   _0xx - general  
#   _1xx - cell/symmetry
#   _2xx - adp-related  
#   _3xx - intra geometry   
#   _4xx - inter geometry   
#   _5xx - coordination geometry
#   _6xx - void tests & varia   
#   _7xx - varia
#   _8xx - (Fatal) Software Errors/Problems 
#   _9xx - Reflection data issues   
#   
# - All tests are defined as two line stanzas   
#   The first line gives the test-number and thresholds (A4, 3A5)   
#      E.g. _klm crit_1 crit_2 crit_3   
#   The second line defines the message (A55).  
#      E.g. 'Structure contains solvent accessible Voids of $F Ang**3'  
#   
#   $I defines where (optionally) an 'integer' threshold/value will be placed   
#   $F defines where (optionally) a 'real' threshold/value will be placed   
#   $A defines where an atom label is inserted (first)  
#   $B defines where an atom label is inserted (second) 
#   $X defines where bond,angle,torsion (calculated) is inserted
#   $Y defines where bond,angle,torsion (reported)   is inserted
#   
# Tests (value > crit) are done from right to left (ie crit_3 crit_2 crit_1)
#   
# ALERT_Level_A = Could Indicate a Serious Problem - Consider Carefully.
# ALERT_Level_B = Might Indicate a Potentially Serious Problem. 
# ALERT_Level_C = Check to Ensure it is OK and not Because of an Oversight. 
# ALERT_Level_G = General Info. Check that it is not Something Unexpected.  
#   
# ALERT_Type_1  = CIF Construction/Syntax Error, Inconsistent or Missing Data.  
# ALERT_Type_2  = Indicator that the Structure Model may be Wrong or Deficient. 
# ALERT_Type_3  = Indicator that the Structure Quality may be Low.  
# ALERT_Type_4  = Cosmetic improvement, Methodology, Query or Suggestion.   
# ALERT_Type_5  = Informative Message, Check.   
#   
# NOTES: - Validation runs invoked with the '-u' option will provide textual
#          information and HELP on the reported ALERTS (and -U without) 
#        - The -G option provides for 'Chem-Mode' (i.e. without Acta
#          specific ALERTS) 
#        - Actual ALERTS start at _002 (Others are pseudo ALERTS)   
#        - Coding on criteria line: A = All, I = IUCr only, O = Obsolete
#        - Four numbers (0 or 1) indicate (and used for counting) respectively  
#          - Missing Experimental Info Issues   
#          - Experimental Data Related Issues   
#          - Structural Model Related Issues
#          - Unresolved or to be Checked Issues 
#
# This file is included in encoded format in the PLATON source code.
# A readable version of this check.def can be extracted from the PLATON
# executable with the terminal command: 'platon -z2'. 
#  
#=============================================================================
# >>> Check for embedded '_shelx_res_file' refinement instruction file (.res)  
_001    0    2    3 1 C   1 0 0 0   
No _shelx_res_file DataName Found in SHELXL CIF      Please Do !

 SHELXL2018 and later will automatically include the final .res in the CIF as   
 an embedded comment preceded by the dataname '_shelx_res_file'.
 That dataname should not be renamed into _iucr_refine_instructions_details.
 This file contains the complete details of the refinement model and can be
 extracted to repeate the refinement recreate the .fcf. 
#=============================================================================
# >>> Report the number of atom sites with distance/angle restraints
_002    0    0    0 2 A   0 0 1 0   
Number of Distance or Angle Restraints on AtSite $I Note

 This ALERT reports the number of atomic sites that are flagged as distance 
 or angle restrained (D-Flag). The associated geometry parameter values may
 be less informative.   
#=============================================================================
# >>> Report the number of non-H atoms with Uiso or U(i,j) restraints  
_003    0    0    0 2 A   0 0 1 0   
Number of Uiso or U(i,j) Restrained non-H-Atoms  $I Report  

 This ALERT reports the number of non-H atoms that are flagged as handled   
 with Uiso or U(i,j) restraints (U-Flag). Their usage may hide unresolved
 disorder issues.   
#=============================================================================
# >>> Report the dimensionality of a polymeric structure  
_004    0    0    0 5 A   0 0 0 0   
Polymeric Structure Found with Maximum Dimension $I Info

 This ALERT reports on polymeric networks and their dimensionality as found in  
 the crystal structure. 
 Note: Polymeric structures can be legitimate or due to an erroneous structure
 analysis.
#=============================================================================
# >>> Check for any embedded refinement instruction file present in the CIF 
_005    0    0    1 5 A   1 0 0 0   
No Embedded Refinement Details Found  in the CIF     Please Do !

 No embedded 'refinement details' records were found in the CIF. Acta Cryst.
 requires the inclusion of the last .res file (in case of a SHELXL, XL or 
 OLEX2 refinement or similar for non-SHELXL refinement programs) in the CIF,   
 embedded between records with semicolons in position 1, preceded by a
 _shelx_res_file or '_iucr_refine_instructions_details' record.  
 Note: SHELXL20xy will automatically include the final .res as an embedded  
 comment with the dataname '_shelx_res_file'.   
#=============================================================================
# >>> Check for extinction parameter refinement 
_006    0    0    0 5 A   0 0 0 0   
Note: Extinction Parameter Refined  = $A           ! Info   

 This ALERT reports the refinement of an extinction parameter.  
 SHELXL corrects Fobs values in the FCF for Extinction. JANA not.   
 Note: Large values of this parameter may be caused by other factors than 
 extinction (e.g. twinning, systematically under or over-estimated
 intensities and other systematic errors).
#=============================================================================
# >>> Report on unrefined Donor-H-atoms 
_007    0    0    0 5 A   0 0 1 0   
Number of Unrefined Donor-H Atoms .............. $I Report  

 It is standard practice to refine H-atoms on hetero atoms such as O & N as
 proof of their correct assignment. 
#=============================================================================
# >>> Check for embedded refinement reflections details file (.hkl)  
_008    0    0    2 5 A   1 0 0 0   
No _iucr_refine_reflections_details   in the CIF     Please Do !

 No reflection records were found in the CIF. Acta Cryst. and 'FAIR' require
 the inclusion of the unmerged reflection file used in the final refinement 
 (.hkl in case of a SHELXL or XL refinement) in the CIF, embedded between
 records with semicolons in position 1 and preceded by an   
 '_iucr_refine_instructions_details' record.
 Note: SHELXL20xy will automatically include the .hkl as an embedded
 comment with the dataname '_shelx_hkl_file'.   
#=============================================================================
# >>> Check for potential radiation type and standard wavelength conflict
_009    0    2    2 1 A   0 0 0 1   
Reported Radiation type and Wavelength Conflict?     Please Check   

 The reported values for _diffrn_radiation_type or _diffrn_radiation_probe and 
 _diffrn_radiation_wavelength should be consistent. This ALERT should catch
 possible cases such as where a synchrotron based dataset is erroneously
 refined with one of the standard wavelengths such as MoKa = 0.71073. 
#=============================================================================
# >>> Test for the availability of reflection data for validation and archival  
_010    0    0    0 1 A   1 0 0 0   
No Suitable  (Embedded) Reflection Data Supplied     Please Do !

 Validation is not complete without the availability of the diffraction data.   
 Deposited reflection data are preferably the set of reflections that were  
 used in the final refinement and embedded in the CIF between records with  
 semicolons in position 1 and preceded by an shelx_hkl_file or
 _iucr_refine_reflections_details record. SHELXL20xy will do that
 automatically. Alternatively, an external file with final observed,
 calculated and sigma reflection data will be the minimum for validation and
 archival.   
#=============================================================================
# >>> Test for any ATOM records found in the CIF   
_011    0    0    0 1 A   0 0 0 0   
No Atoms Found in the Supplied CIF .............     Please Check   

 No atom coordinates were detected in the CIF prior to the U(i,j) loop. The 
 atom labels in both loops should be identical in order to be associated with
 each other. 
#=============================================================================
# >>> Check for the presence of a valid _shelx_res_checksum record in the CIF  
_012    0    0  1.0 1 A   1 0 0 0   
$A_shelx_res_checksum Found in CIF ......     Please Check  

 The supplied CIF contains a '_shelx_res_file' record but not a valid   
 associated '_shelx_res_checksum' record. A valid pair of embedded .res and 
 .hkl files allows the automatic creation of a .fcf file with SHELXL20xy to be  
 used for a detailed analysis of the refinement result. A file is valid when
 the calculated and reported checksums are identical. Only characters with an   
 ASCII value higher than 32 contribute to the checksum. An embedded .res file
 might be broken, either due to tranfer errors or to deliberate or accidental
 post-refinement editing of its content. Please re-refine after implementing
 any changes to the .res file.  
#=============================================================================
# >>> Check for the presence of a valid _shelx_hkl_checksum record in the CIF 
_013    0    0  1.0 1 A   1 0 0 0   
$A_shelx_hkl_checksum Found in CIF ......     Please Check  

 The supplied CIF contains a '_shelx_hkl_file' record but not a valid   
 associated '_shelx_hkl_checksum' record. A valid pair of embedded .res and 
 .hkl files allows the automatic creation of a .fcf file with SHELXL20xy to be  
 used for a detailed analysis of the refinement result. A file is valid when
 the calculated and reported checksums are identical. Only characters with an   
 ASCII value higher than 32 contribute to the checksum. 
 An embedded .res file might be broken, either due to tranfer errors or to  
 deliberate or accidental post-refinement editing of its content.   
#=============================================================================
# >>> Check for the presence of a valid _shelx_fab_checksum record in the CIF
_014    0    0  1.0 1 A   1 0 0 0   
$A_shelx_fab_checksum Found in CIF ......     Please Check  

 The supplied CIF contains a '_shelx_fab_file' record but not a valid   
 associated '_shelx_fab_checksum' record. A valid pair of embedded .res and 
 .hkl files allows the automatic creation of a .fcf file with SHELXL20xy to be  
 used for a detailed analysis of the refinement result. A file is valid when
 the calculated and reported checksums are identical. Only characters with an   
 ASCII value higher than 32 contribute to the checksum. An embedded .res file
 might be broken, either due to tranfer errors or to deliberate or accidental
 post-refinement editing of its content.   
#=============================================================================
# >>> Check for refinement reflections details (SHELXL20xy) 
_015    0    0    0 5 A   1 0 0 0   
No _shelx_hkl_file Record in SHELXL20xy CIF ....     Please Do !

 No embedded reflection record was found in the CIF file that was created with  
 SHELXL20xy (or XL). SHELXL20xy automatically includes the '.hkl' file that 
 was used in the refinement (along with the final '.res' file) as an embedded   
 comment with the dataname '_shelx_hkl_file'. Do not change this dataname   
 in _iucr_refine_reflections_details. Such a record is useful for archival  
 and follow-up calculations.
#=============================================================================
# >>> Check for refinement FAB file (SHELXL20xy)
_016    0    0    0 5 A   1 0 0 0   
No _shelx_fab_file Record in SHELXL20xy CIF ....     Please Supply  

 No embedded .fab record was found in the CIF file that was created with
 SHELXL20xy (or XL). SHELXL20xy automatically includes the '.fab' file that 
 was used in the refinement (along with the final '.res' & '.hkl' files) as 
 an embedded comment with the dataname '_shelx_fab_file'. Do not change this
 dataname. Such a record is useful for archival and follow-up calculations. 
#=============================================================================
# >>> Check the consistency of scattering Type  
_017 0.00 0.00 0.00 1 A   0 0 1 0   
Check Scattering Type Consistency of $Aas  $B   

 Check for the correct scattering type assignment to this atom. 
#=============================================================================
# >>> Check _diffrn_measured_fraction_theta_max and *_full equality  
_018 0.00 1.00 2.00 1 A   0 0 0 0
_diffrn_measured_fraction_theta_max .NE. *_full           ! Check

 The values of '_diffrn_reflns_theta_max' and '_diffrn_reflns_theta_full'
 are  reported as equal. However, the associated reported values of
 '_diffrn_measured_fraction_theta_max'  and
 '_diffrn_measured_fraction_theta_full' are not equal. This is inconsistent.

 CIF Dataname Definitions:
 _diffrn_measured_fraction_theta_max:
    Fraction of unique (symmetry-independent) reflections measured out to
    '_diffrn_reflns_theta_max'.
 _diffrn_measured_fraction_theta_full:
    Fraction of unique (symmetry-independent) reflections measured out to
    '_diffrn_reflns_theta_full'.
 _diffrn_reflns_theta_max:
   Maximum theta angle in degrees for the measured intensities. The fraction
   of unique reflections measured out to this angle is given by
   '_diffrn_measured_fraction_theta_max'.
 -diffrn_reflns_theta_full:
    The theta angle (in degrees) at which the measured reflection count is
    close to complete. The fraction of unique reflections measured out to
    this angle is given by '_diffrn_measured_fraction_theta_full'.
#=============================================================================
# >>> Check _diffrn_measured_fraction_theta_max/full consistency
_019 0.00 0.02 1.00 1 A   0 1 0 0   
_diffrn_measured_fraction_theta_full/*_max < 1.0 $F Report  

 The reported value of _diffrn_measured_fraction_theta_full is less than
 the reported value of _diffrn_measured_fraction_theta_max. Their ratio is  
 reported when less than 1.0. When theta_full is less than theta_max such   
 a value indicates that there are relatively more reflections missing at
 lower resolution.
 The measured fraction (completeness) is expected to be higher at a lower
 theta_full value.
 Usually, a theta_full value corresponding to sin(theta)/lambda = 0.6 should
 give a satisfactory data completeness value.

 CIF Dataname Definitions:
 _diffrn_measured_fraction_theta_max:
    Fraction of unique (symmetry-independent) reflections measured out to
    out to '_diffrn_reflns_theta_max'.
 _diffrn_measured_fraction_theta_full:
    Fraction of unique (symmetry-independent) reflections measured out to
    out to '_diffrn_reflns_theta_full'.
 _diffrn_reflns_theta_max:
   Maximum theta angle in degrees for the measured intensities. The fraction
   of unique reflections measured out to this angle is given by
   '_diffrn_measured_fraction_theta_max'.
 -diffrn_reflns_theta_full:
    The theta angle (in degrees) at which the measured reflection count is
    close to complete. The fraction of unique reflections measured out to
    this angle is given by '_diffrn_measured_fraction_theta_full'.
#=============================================================================
# >>> Check for unusually high Rint value
_020 0.12 0.18 0.25 3 A   0 1 0 0   
The Value of Rint is Greater Than 0.12 ......... $F Report  

 The value of Rint (i.e. _diffrn_reflns_av_R_equivalents) should normally be
 considerably less than 0.12 and in the order of magnitude of the reported  
 R-values. Rint may be relatively meaningless when based on a very limited  
 number of averaged data. Higher values should be accompanied by a suitable 
 explanation in the _publ_section_exptl_refinement section. However,
 authors should first ensure that there are not overlooked problems 
 associated with the data or the space-group. Elevated values for   
 _diffrn_reflns_av_R_equivalents may be indicative of a need to recollect   
 the data from a crystal of higher quality or that there is a problem with  
 the data treatment. Consider the following 
 (a) The absorption corrections are inadequate or inappropriate.
 (b) The overall quality of the data may be poor due to the crystal quality.
 (c) The crystal is very weakly diffracting, so that a large proportion of  
     essentially "unobserved" reflections are being used in the refinement. 
     You should consider using a better crystal or a data collection at 
     low temperature and/or, if the compound is organic, using Cu radiation.
 (d) You are working in the wrong crystal system or Laue group. 
 (e) You have only a very small number of equivalent reflections, which 
     may lead to artificially high values of _diffrn_reflns_av_R_equivalents

 Note that if _diffrn_reflns_av_sigmaI/netI is also large, the quality  
 of the data should be considered to be suspect.
#=============================================================================
# >>> Check expected number of reflections (Max = 1 Centro, 2 - non-centro) 
_021 0.01 0.05 100. 4 A   0 1 0 0   
Ratio Unique / Expected Reflections too High ... $F 

 The expected number of reflections corresponds to that in the asymmetric   
 unit of the Laue group. Expected ratio: less-or-equal 1 for centro symmetric   
 structures and less than 2 for non-centrosymmetric structures. 
 Reasons to exceed those numbers can be:
  1 - Systematic absencies not omitted from the observed data count.
  2 - Refinement with redundant (i.e. not merged/unique) data set.  
  3 - SHELXL HKLF 5 Refinement  
#=============================================================================
# >>> Check expected number of reflections (completeness)   
_022 0.05 0.10 0.15 3 A   0 1 0 0   
Ratio Unique / Expected Reflections (too) Low .. $F 

 Test for data completeness. The ratio of the reported number of unique 
 reflections and expected number of reflections for the resolution given is 
 reported. The ratio can be low due to a missing cusp of data when collected
 with a 2D-detector. Alternatively, the wrong asymmetric part of reciprocal 
 space was collected on a serial detector system.   
#=============================================================================
# >>> Check Theta-Max   
_023 .010 .025 0.05 3 A   0 1 0 0   
Resolution (too) Low [sin(theta)/Lambda < 0.6].. $F Ang-1   

 Check resolution of the data set. This alert is issued when sin(theta)/lambda
 < 0.6 (i.e. theta < 25.24 degree for MoKa or 67.7 degree for CuKa radiation).
 In principle, all observed data should be included in the refinement.
 Alternatively, a sin(theta)/Lambda cutoff value can be used at a value where
 average(I/sigma(I)) < 2 in order not to refine on noise.
#=============================================================================
# >>> Check for Hmin..Lmax  
_025 .000 .000 2.00 1 A   1 0 0 0   
Hmin..Lmax Data Incomplete or Missing ..........     Please Check   

 Check reported h,k,l - range with calculated range based on reported 
 theta-max.
#=============================================================================
# >>> Check for a weak data set 
_026   50   60   70 3 A   0 1 0 0   
Ratio Observed / Unique Reflections (too) Low ..$I% Check   

 Check whether a sufficient fraction of the unique data set is indeed above  
 the 2 * sigma(I) level.

 All reflection data are included in this test. Check whether this low ratio
 is caused by weak data beyond sin(theta)/lambda > 0.5 (i.e. low resolution).   
#=============================================================================
# >>> Check _diffrn_reflns_theta_full   
_027  .06  .07  .08 3 A   0 1 0 0   
_diffrn_reflns_theta_full value (too) Low ...... $F Degree  

 Ideally (and a requirement for publication in Acta Crystallographica), 
 the dataset should be essentially complete, as defined by  
 -diffrn-measured-fraction-theta-full (close to 1.0), up to 
 sin(theta)/lambda = 0.6 (i.e. 25.24 degrees MoKa). 
 The three major causes of incomplete data sets are:
 1 - A missing cusp of data due to data collection by rotation around   
     the spindle axis only (standard on some image-plate systems).  
     Cure: collect an additional data set after remounting the crystal. 
 2 - The DENZO image processing package has problems with certain strong
     reflections. They are often excluded from the data set.
     Cure: Add an additional scan at lower power setting in order to include
     strong low order reflections.  
 3 - Incomplete scans.  
#=============================================================================
# >>> Check the reported _diffrn_measured_fraction_theta_max
_028 .050 .100 0.15 3 A   0 1 0 0   
_diffrn_measured_fraction_theta_max Value Low .. $F Why?

 Ideally, the reported '_diffrn_measured_fraction_theta_max' value, 
 corresponding to theta-max, should be close to 1.0.
#=============================================================================
# >>> Check the reported _diffrn_measured_fraction_theta_full   
_029 .020 .040 .060 3 A   0 1 0 0   
_diffrn_measured_fraction_theta_full value Low . $F Why?

 Ideally (and a requirement for publication in Acta Crystallographica), 
 this fraction should be close to 1.0 for theta-full greater or equal   
 to sin(theta/lambda) = 0.6 (i.e. 25.24 degrees for MoKa and 67.7 degrees   
 for CuKa  radiation).  
 The three major causes of incomplete data sets are:
 1 - A missing cusp of data due to data collection by rotation around   
     the spindle axis only (standard on some image-plate systems).  
     Cure: collect an additional data set after remounting the crystal. 
 2 - The DENZO imageprocessing package has problems with certain strong 
     reflections. They are often excluded from the data set.
     Cure: Add an additional scan at lower power setting in order to
     include strong low order reflections.  
 3 - Incomplete scans, possibly based on erroneously assumed higher than
     actual symmetry.   

 Note: The default value of _diffrn_measured_fraction_theta_full that   
 is automatically calculated and inserted in the CIF by SHELXL-97 might 
 generate A-level ALERTS when significant numbers of reflections are
 missing at higher theta values. In order to avoid such an ALERT,   
 substitute the values calculated with the SHELXL instruction 'ACTA 50' 
 for _diffrn_reflns_theta_full and _diffrn_measured_fraction_theta_full 
 respectively. For Mo-radiation, corresponding values of 25 degees (or  
 higher) and 0.99 (or higher) are expected. (See SHELXL manual).
 PLATON may be used to analyse the case at hand (by invoking either the 
 'FCF-VALIDATION' mode or the 'ASYM-VIEW' mode).
#=============================================================================
# >>> Check _diffrn_reflns_number >= reflns_number_total
_030    0    2    2 1 A   0 0 0 0   
_diffrn_reflns_number   <   _reflns_number_total     Please Check   

 The number of measured reflections should be equal or greater than the 
 number of unique reflections.  
#=============================================================================
# >>> Check need for extinction correction parameter
_031  0.3  0.4  1.0 4 A   0 1 0 0   
Refined Extinction Parameter Within Range of ... $F Sigma   

 This test checks whether a refined extinction parameter is meaningful  
 i.e. whether its value is significantly larger than its corresponding s.u. 
 If not, this parameter should be removed from the model and the structure  
 refined without this meaningless additional parameter. 
 The current default gives a warning when its value is within 3.33 s.u. 
 SHELXL97-2 will not allow negative values leading to ill-convergence and   
 non-zero maximum shift/error values: remove extinction parameter from the  
 refinement.
#=============================================================================
# >>> Check s.u. Flack parameter
_032  0.2 10.0 10.0 4 A   0 0 0 0   
Std. Uncertainty on Flack Parameter Value High . $F Report  

 Check the validity of the absolute structure determination.
 A high s.u. indicates that the experimental data do not support the
 determination of the absolute structure. This will generally be the case   
 with light atom MoKa data where f" is nearly zero. 
 Note: Use the TWIN & BASF 0.0 instructions in SHELXL97. The default
 FLACK parameter is not always reliable, in particular when strongly
 correlated with the position of the origin (e.g. along y in space-group P21).  
 Please refer to Flack,H.D. & Bernardinelli, G. (1999) Acta Cryst. A55, 
 908-915 and (2000) J. Appl. Cryst., 33, 1143-1148. 
#=============================================================================
# >>> Check Flack parameter value   
_033  0.3 10.0 10.0 4 A   0 0 0 0   
Flack x Value Deviates > 3.0 * sigma from Zero . $F Note

 Check the relevance/validity of the absolute structure determination. Please
 refer to Flack,H.D. & Bernardinelli, G. (1999) Acta Cryst. A55, 908-915 and
 (2000) J. Appl. Cryst., 33, 1143-1148. A value of the Flack parameter that
 deviates significantly from zero  (taking into account the associated s.u.)
 might indicate that the absolute structure should be inverted in case of a
 value closer to 1.0 than to zero. A value close to 0.5 may be indicative of
 an inversion twin or a missed centre of inversion. For valid absolute
 structure assignments, abs(x) should be less than 2 * s.u., with s.u. < 0.04.
 For enantiopure compounds, s.u. should be less than 0.1.  
#=============================================================================
# >>> Check for Flack parameter value specified Z>Si, non-centro
_034    0    2    2 1 A   0 0 0 0   
No Flack Parameter Given. Z > Si, NonCentro ....     Please Do !

 No Flack parameter value given for non-centrosymmetric structure with  
 heaviest atom Z > Si. This might be intentional.   
#=============================================================================
# >>> Check for _chemical_absolute_configuration
_035    0    0    2 1 A   1 0 0 0   
_chemical_absolute_configuration Info  Not Given     Please Do !

 Options are 'rm', 'ad', 'rmad', 'syn', 'unk' or '.'

 rm   : absolute configuration established by the structure determination   
        of a compound containing a chiral reference molecule of known   
        absolute configuration. 
 ad   : absolute configuration established by anomalous dispersion effects  
        in diffraction measurements on the crystal. 
 rmad : absolute configuration established by the structure determination   
        of a compound containing a chiral reference molecule of known   
        absolute configuration and confirmed by anomalous dispersion
        effects in diffraction measurements on the crystal. 
 syn  : absolute configuration has not been established by anomalous
        dispersion effects in diffraction measurements on the crystal.  
        The enantiomer has been assigned by reference to an unchanging  
        chiral centre in the synthetic procedure.   
 unk  : absolute configuration is unknown, there being no firm chemical 
        evidence for its assignment to hand and it having not been  
        established by anomalous dispersion effects in diffraction  
        measurements on the crystal. An arbitrary choice of enantiomer  
        has been made.  
 .    : inapplicable.   
#=============================================================================
# >>> Check for missing Flack parameter s.u.
_036  0.5  2.0  2.0 1 A   1 0 0 0   
No s.u. Given for Flack Parameter ..............     Please Do !

 No standard uncertainty found for the Flack parameter. When the structure
 refinement was done with SHELXL97-2, the likely reason for this is a missing
 BASF instruction. This applies in particular when the associated Flack
 parameter has the value 0.000. No valid conclusions on the absolute structure
 can be drawn in that case.  
#=============================================================================
# >>> Check _diffrn_reflns_theta_full   
_037    0    0    0 1 I   1 0 0 0   
_diffrn_reflns_theta_full ............ Not Given     Please Do !

 No information is given about the theta value for which the dataset is 
 complete, subject to the percentage given with the dataname
 _diffrn_measured_fraction_theta_full.  
#=============================================================================
# >>> Check _diffrn_measured_fraction_theta_max 
_038    0    0    0 1 I   1 0 0 0   
_diffrn_measured_fraction_theta_max  Not Given .     Please Do !

 This fraction should be specified in combination with the theta value given 
 with the dataname _diffrn_reflns_theta_full. 
#=============================================================================
# >>> Check _diffrn_measured_fraction_theta_full
_039    0    0    0 1 I   1 0 0 0   
_diffrn_measured_fraction_theta_full Not Given .     Please Do !

 This fraction should be specified in combination with the value for
 _diffrn_reflns_theta_max.  
#=============================================================================
# >>> Test for H-atoms [0,1]
_040  0.0 99.0 99.0 1 A   0 0 1 0   
No H-atoms in this Carbon Containing Compound ..     Please Check   

 Alert for 'no H-atoms' in CIF. This is unusual for carbon containing
 compounds, but may be correct.
#=============================================================================
# >>> Test sum formula   
_041  0.0 99.0 99.0 1 A   0 0 0 1   
Calc. and Reported SumFormula    Strings  Differ     Please Check   

 In the ideal case, both SumFormula strings (reported and calculated) should
 be identical. If not, the reason for the difference should be clear. Examples  
 are cases where populations do not add up to integer numbers, or when solvent  
 molecules have been SQUEEZED.  
 Note: SHELXL97 reports population parameters in the CIF with two decimals  
 only. This may lead to non-integer atom counts in cases of disorder
 due to rounding.   
 Note: Alerts _041, _042 & _045 can probably be ignored when the relevant   
 values differ by the same factor.  
#=============================================================================
# >>> Test moiety formula
_042  0.0 99.0 99.0 1 I   0 0 0 1   
Calc. and Reported MoietyFormula Strings  Differ     Please Check   

 In the ideal case, the MoietyFormula string as reported should be identical
 to the MoietyFormula string calculated from the data in the CIF. If not, the   
 reason should be clear. Examples are cases where there is no separating space  
 between two element names or cases where populations do not add up to  
 integer numbers or when moieties are separated by '.' instead of ','.  

 Example: NO3 should be given as N O3   

 Note: Alerts _041, _042 & _045 can probably be ignored when the relevant   
 values differ by the same factor.  
#=============================================================================
#1>>> Test for molecular weight
_043  0.1  1.0 10.0 1 A   0 0 0 1   
Calculated and Reported Mol. Weight Differ by .. $F Check   

 Note: atomic weights used in the calculation of the molecular weight are   
 taken from Inorg. Chim. Acta 217 (1994) 217-218 which deviate in a few cases   
 slightly from the older values used in SHELXL97-2. 
 Note: The tabulated atomic weights that are used may deviate from the actual
 value in case of special isotopes of e.g. Uranium or Plutonium. 
#=============================================================================
#1>>> Check reported against calculated density
_044  1.0  5.0 10.0 1 A   0 0 0 1   
Calculated and Reported Density Dx  Differ by .. $F Check   

 In the ideal case, both data items should be the same within a small   
 tolerance. If not, the reason should be clear. Check also whether the
 density value is reported in the CIF.
#=============================================================================
#1>>> Check reported and calculated Z   
_045  0.0  0.0  0.0 1 A   0 0 0 1   
Calculated and Reported Z Differ by a Factor ...  $A Check   

 In the ideal case, both data items (Z(calc) & Z(reported)) should be   
 the same. If not, the reason for the difference should be clear. An example
 is the situation where PLATON gives Z = 1 when the program cannot work out 
 a proper Z.

 Note: Alerts _041, _042 & _045 can probably be ignored when the relevant   
 values differ by the same factor.  
#=============================================================================
#1>>> Check reported density with calculated density from Z * MW  
_046  1.0  5.0 10.0 1 A   0 0 0 1   
Reported Z, MW and D(calc) are Inconsistent .... $F Check   

 D(calc) as calculated from the reported Z and MW is compared for consistency   
 with the reported d(calc). 
#=============================================================================
#1>>> Test sum formula given 
_047  0.0  0.0  0.0 1 A   1 0 0 0   
SumFormula Not Given ...........................     Please Do !

 The Sumformula, corresponding with the Moietyformula, should be given. 
#=============================================================================
#1>>> Test moiety formula given  
_048  0.0 99.0 99.0 1 I   1 0 0 0   
MoietyFormula Not Given (or Incomplete) ........     Please Check   

 The Moiety formula (i.e. the specification of the various species in the   
 structure) should be given in the CIF. 

 Example: '(Cd 2+)3, (C6 N6Cr 3-)2, 2(H2 O)'
#=============================================================================
# >>> Check calculated density > 1.0 
_049  0.0  0.0  1.0 1 A   0 0 0 1   
Calculated Density Less Than 1.0 gcm-3 ......... $F Check   

 The calculated density will with a few exceptions be larger than 1.0.  
 A smaller value may indicate either an incomplete model or incorrect   
 symmetry. (e.g. a missing 'bar' in P-1 etc.)   
#=============================================================================
# >>> Test for mu given [0,1]   
_050  0.0  0.0  0.0 1 A   1 0 0 0   
Absorption Coefficient mu Not Given ............     Please Do !

 The linear absorption coefficient corresponding to the Sumformula should be
 given. 
#=============================================================================
# >>> Test for difference mu(cif) with mu(calc) [%] 
_051    1    5   10 1 A   0 0 0 1   
Mu(calc) and Mu(cif) Ratio Differs from 1.0 by . $F %   

 In the ideal case, both Mu(calc) and Mu(cif) values should be the same within
 a small tolerance. If not, the reason for the difference should be clear.
 PLATON/checkCIF calculates Mu(calc) based on mu/Rho values tabulated in the
 Int. Tables for wavelengths Cu(Ka), Mo(Ka) and Ag(Ka). For other wavelengths, 
 such as those for Synchrotron, Ga(Ka) and In(Ka) sources, those values are
 calculated following S. Brennan & P.L. Cowan (1992). Rev. Sci. Instr., 63,
 850-853. Those values may differ slightly from values calculated with
 alternative external tools, in particular for wavelengths near absorption
 edges. The mu/Rho values used by PLATON/checkCIF for other wavelengths can be
 listed with the PLATON instruction 'ANOM wavelength'.  
#=============================================================================
# >>> Test for specification absorption correction method [0,1] 
_052  0.0 99.0 99.0 1 A   1 0 0 0   
Info on Absorption Correction Method   Not Given     Please Do !

 The treatment/method of absorption(correction) should be given explicitly. 
 Set _exptl_absorpt_correction_type to 'none' when no correction is done.   
 Other recognized values are 'psi-scan', 'empirical', 'multi-scan', 
 'refdelf', 'analytical', 'numerical', 'gaussian'.  
#=============================================================================
# >>> Test for specification xtal_dimension_min [0,1]   
_053  0.0  2.0  2.0 1 I   1 0 0 0   
Minimum Crystal Dimension Missing (or Error) ...     Please Check   

 The smallest crystal dimension should be supplied in the CIF.  
 The expected value should be a real number (i.e. not 0.35mm)   
#=============================================================================
# >>> Test for specification xtal_dimension_mid [0,1]   
_054  0.0  2.0  2.0 1 I   1 0 0 0   
Medium  Crystal Dimension Missing (or Error) ...     Please Check   

 The medium crystal dimension should be supplied in the CIF.
 The expected value should be a real number (i.e. not 0.35mm)   
#=============================================================================
# >>> Test for specification xtal_dimension_max [0,1]   
_055  0.0  2.0  2.0 1 I   1 0 0 0   
Maximum Crystal Dimension Missing (or Error) ...     Please Check   

 The largest crystal dimension should be supplied in the CIF.   
 The expected value should be a real number (i.e. not 0.35mm)   
#=============================================================================
# >>> Test for specification xtal_radius [0,1]  
_056  0.0  0.0  0.0 1 I   1 0 0 0   
Crystal Radius Missing for Spherical Correction      Please Do !

 Spherical correction for absorption is reported. The radius used is not
 supplied.  
#=============================================================================
# >>> Test for correction for absorption needed 
_057  1.1  1.2  1.3 3 A   0 1 0 0   
Correction for Absorption Required   RT(exp) ... $F Do !

 You have indicated that an absorption correction has not been applied. 
 (_exptl_absorpt_correction_type 'none'). However, the predicted values of  
 Tmin & Tmax, based on the crystal dimensions given in the CIF, are 
 sufficiently unequal that absorption effects appear to be significant. 
 Therefore, the application of a suitable absorption correction would   
 appear to be required. Also check that the crystal dimensions given in the 
 CIF do represent the actual crystal dimensions as closely as possible. 
 Inaccuracies here can lead to a poor prediction of Tmin & Tmax and give
 rise to these alerts. It should normally be possible to estimate the   
 crystal dimensions to 2 decimal places. Rough estimates to only 1 decimal  
 place may be too inaccurate to provide reliable estimates of Tmin & Tmax.  
#=============================================================================
# >>> Test for specification Tmax [0,1] 
_058  0.5  0.5  0.5 1 A   1 0 0 0   
Maximum Transmission Factor Missing ............          ? 

 The Maximum transmission factor should be specified in the case a correction   
 for absorption was done. This is NOT the value that is calculated  
 automatically with SHELXL when a SIZE instruction is given in the SHELXL   
 instruction file. The values reported by SHELXL represent the EXPECTED 
 correction range. Some correction packages (e.g. SADABS) will provide  
 only one 'relative- correction-factor'. In such cases, Tmax should be  
 given as Tmax-expected and Tmin = relative-correction-factor * Tmax.   
#=============================================================================
# >>> Test for specification Tmin [0,1] 
_059  0.5  0.5  0.5 1 A   1 0 0 0   
Minimum Transmission Factor Missing ............          ? 

 The Minimum transmission factor should be specified in case a correction   
 for absorption was done. This is NOT the value that is calculated  
 automatically with SHELXL when a SIZE instruction is given in the SHELXL   
 instruction file. The values reported by SHELXL represent the EXPECTED 
 correction range. Some correction packages (e.g. SADABS) will provide  
 only one 'relative-correction-factor'. In such cases, Tmax should be   
 given as Tmax-expected and Tmin = relative-correction-factor * Tmax.   
#=============================================================================
# >>> RR test   
_060 1.10 1.50 2.00 4 I O 0 0 0 0   
Ratio Tmax/Tmin (Exp-to-Rep) (too) Large ....... $F 

 see IUCR WEB-Pages 
#=============================================================================
# >>> RR' test  
_061 0.10 0.25 0.50 4 I O 0 0 0 0   
Tmax/Tmin Range Test RR' too Large ............. $F 

 see IUCR WEB-Pages 
#=============================================================================
# >>> Rescale Tmin & Tmax   
_062    0    2    2 4 I O 0 0 0 0   
Rescale T(min) & T(max) by ..................... $F 

 Some (empirical) correction packages (e.g. SADABS) will provide only one   
 'relative-correction-factor'. In such cases, Tmax should be given as   
 Tmax-expected (as calculated from the crystal dimensions) and  
 Tmin = relative-correction-factor * Tmax.  
#=============================================================================
# >>> Test for crystal size 
_063  0.6  0.6  5.0 4 I   0 0 0 1   
Crystal Size Possibly too Large for Beam Size .. $F mm  

 Alert for crystals with at least one dimension probably too large for the  
 homogeneous part of the X-ray beam when used for datacollection using  
 crystal monochromated radiation. An exception will be datacollection using 
 a beta-filter and a sufficiently large collimator. 

 See also: C.H.Gorbitz (1999), Acta Cryst. B55, 1090-1098.  
#=============================================================================
# >>> Test for T(max) >= T(min)   
_064  0.0  0.0  0.0 1 A   0 0 0 0   
Reported T(min) is Greater than Reported T(max) .         ! 

 Check that the values entered under _exptl_correction_T_min and
 _exptl_correction_T_max have not been reversed or if there is a
 typographical error for one of these two items.
#=============================================================================
# >>> Test for applicability of (semi-)empirical absorption correction [0,1]
_065  3.0  3.0  3.0 3 A O 0 0 0 0   
Numerical Correction Might be Beneficial: mu*mid $F Note

 For high mu * mid values, numerical absorption correction procedures are   
 recommended (either based on Gaussian integration or analytical) in case of
 homogeneous beam profiles and crystals small enough to fit within the  
 homogeneous part of the X-ray beam.
 In case of in-homogeneous beams, a combination of numerical crystal face   
 based correction and multi-scan correction is recommended. 
#=============================================================================
# >>> Test whether predicted and reported transmission ranges are identical 
_066  0.0  2.0  2.0 1 I   0 0 0 0   
Predicted and Reported Tmin&Tmax Range Identical          ? Check   

 The predicted and reported transmission ranges are found to be identical   
 which is not to be expected. CIF's generated with SHELXL97 report  
 transmission ranges based on the crystal dimensions supplied on the
 SIZE card. Those values have nothing to do with the actual corrections 
 for absorption as applied to the data: they just report the EXPECTED range.
 Some correction packages (e.g. SADABS) will provide only one   
 'relative-correction-factor'. In such cases, Tmax should be given as   
 Tmax-expected and Tmin = relative-correction-factor * Tmax.
#=============================================================================
# >>> Ensure that minimum dimension < maximum dimension  
_067  0.0  0.0  0.0 1 I   0 0 0 1   
Maximum Dimension Less Min. Xtal Dimension .....     Please Check   

 Minimum an Maximum dimensions are likely exchanged in the CIF. 
#=============================================================================
# >>> Test for F000 calc/reported difference
_068 0.01 10.0 10.0 1 I   0 0 0 1   
Reported F000 Differs from Calcd (or Missing)...     Please Check   

 In the ideal case, both data items should have the same value. If not, 
 the reason should be clear. A reason might be the output by SHELXL 
 of population parameters to the CIF with only two decimals.

 Note: SHELXL counts the number of electrons in the unit cell. The result   
 will in general be an integer. This is also the number checked for here.   
 The official definition calls for 'The effective number of electrons in the
 crystal unit cell contributing to F(000)'. It may contain dispersion   
 contributions and is calculated as:

 F(000) = [ (sum f~r~)^2^ + (sum f~i~)^2^ ]^1/2^

 f~r~ = real part of the scattering factors at theta = 0
 f~i~ = imaginary part of the scattering factors at theta = 0   
#=============================================================================
# >>> Test for label without numerical part 
_069  0.0  2.0  2.0 1 I   0 0 0 1   
Atom Label Without Numerical Part ..............  $A Do !   

 Acta Cryst. Notes for Authors requires atom labels to contain a numerical  
 part. E.g. A label of the type 'O' should be given as 'O1'.
 This is not necessarily a requirement for other journals.  
#=============================================================================
# >>> Test for duplicate labels 
_070  0.0  0.0  0.0 1 A   0 0 0 1   
Duplicate Atomic Label on INPUT ................  $A Note   

 The CIF contains duplicate labels posing interpretation problems for   
 PLATON/CHECK. Derived geometry ALERTS may have their origin in this problem.
#=============================================================================
# >>> Test for uninterpretable labels   
_071    0    0    0 1 A   0 0 0 1   
Uninterpretable Atom Label on Input ............  $A Note   

 The CIF contains labels posing problems for PLATON/CHECK.  
 Example: label HN1 with no scattering type information supplied.   
 Validation is aborted. 
#=============================================================================
# >>> Test for extreme first weighting parameter value (SHELXL) 
_072  0.1  0.2  0.3 2 A   0 0 0 1   
SHELXL First  Parameter in WGHT  Unusually Large $F Report  

 The first parameter on the SHELXL weighting line and used in the refinement
 has an exceptionally large value. SHELXL will recommend 'WGHT 0.2 0.0' to
 be used in the next refinement when it judges that the refined weight
 parameters values to be excessive. This points to a likeable problem with the
 reflection data and/or the refinement model such as improper reflection
 s.u.'s or an unresolved problem such as missed twinning.
#=============================================================================
# >>> Test for inconsistency 'constr' versus 'H-atoms refined'  
_073    0    0    0 1 I   0 0 0 1   
H-atoms ref, but _hydrogen_treatment Reported as  $A Check  

 The structure contains refined hydrogen atoms. However the data item   
 _refine_ls_hydrogen_treatment has the value 'constr'.  
 The value 'mixed' is more appropriate. 
#=============================================================================
# >>> Test for occupancy = 0.0 (dummy atoms) 
_074  0.0  0.0  0.0 1 A   0 0 0 1   
Occupancy Parameter = 0.0 for ..................  $A Check  

 The CIF contains an atom with occupancy less than 0.0001
 Please check whether the zero occupancy specification is intended. 
#=============================================================================
# >>> Test for occupancy > 1.0   
_075  0.0  0.0  0.0 1 A   0 0 0 1   
Occupancy $F Greater Than 1.0 for ......    $A  

 The CIF contains an atom with Occupancy greater than 1.0.  
#=============================================================================
# >>> Test for occupancy < 1.0 for atom on special position 
_076  0.0  1.0  1.0 1 A   0 0 0 1   
Occupancy $F Less Than 1.0 for Sp.pos  .    $A  

 The CIF contains an atom sitting on a special position with occupancy  
 specified as less than 1.0. This is often an error and the result of the   
 confusion of the notions 'occupancy' and 'population parameter'. The first 
 should be 1.0 for a fully occupied site. The latter multiplies the 
 site-symmetry with the occupancy. Thus, for a fully occupied site on a 
 mirror plane the site-symmetry will be 0.5 * 1.0 = 0.5.
 Note: a wrong occupancy number will lead to an incorrect expected chemical
 formula.  
#=============================================================================
# >>> Test for non-integral # of atoms in unit cell 
_077  0.0  1.0  1.0 4 A   0 0 0 1   
Unitcell Contains Non-integer Number of Atoms ..     Please Check   

 The unit-cell contains a non-integer number of atoms of a given atom type. 
 Valid reasons include partially occupied (solvent) sites and substitutional
 disorder.  
#=============================================================================
# >>> Test for inconsistency 'geom' versus 'no H-atoms' 
_078    0    0    0 1 I   0 0 0 1   
No H-atoms, but _solution_hydrogens Reported as   $A Check  

 The structure contains no hydrogen atoms. However the data item
 _atom_sites_solution_hydrogen had the value 'geom'. This value is likely the
 SHELXL default and should be replaced by '.'.   
#=============================================================================
# >>> Test for inconsistency 'mixed' versus 'no H-atoms'
_079    0    0    0 1 I   0 0 0 1   
No H-atoms, but _hydrogen_treatment Reported as   $A Check  

 The structure contains no hydrogen atoms. However the data item
 _refine_ls_hydrogen_treatment has the value 'mixed'. This value is likely the
 SHELXL default and should be replaced by '.'.   
#=============================================================================
# >>> Test maximum shift/error value 
_080 0.05 0.10 0.20 2 A   0 0 1 0   
Maximum Shift/Error ............................ $F Why ?   

 Convergence of the refinement is proved with a close to zero shift/error   
 value for all refined parameters. Such a convergence is easily achieved
 with a few additional refinement cycles at little cost.
 Note: Some SHELXL-97 versions do not allow for negative Flack parameter
 values. Convergence in such a case may be never reached because the Flack
 parameter value is reset to zero.
#=============================================================================
# >>> Test for  maximum shift/error given   
_081 0.00 0.00 0.00 1 A   0 0 0 1   
No Maximum Shift/Error Given ...................     Please Do !

 A maximum shift/error should be specified in order to judge convergence.   
#=============================================================================
# >>> Test for reasonable R1 value
_082 0.10 0.15 0.20 2 A   0 0 1 0   
High R1 Value .................................. $F Report  

 A higher than usual R1 indicates either an insufficient model or poor  
 quality data.  
#=============================================================================
# >>> Test for extreme second weighting parameter value (SHELXL)
_083  5.0 25.0 50.0 2 A   0 0 0 1   
SHELXL Second Parameter in WGHT  Unusually Large $F Why ?   

 The second parameter on the SHELXL weighting line has an exceptionally large 
 value. This may indicate either improper reflection s.u.s or an unresolved
 problem such as missed twinning. 
#=============================================================================
# >>> Test for reasonable wR2 value   
_084 0.25 0.35 0.45 3 A   0 0 1 0   
High wR2 Value (i.e. > 0.25) ................... $F Report  

 wR2 will in general have a value twice of that of R1 with refinement on F**2.  
 Significantly larger values usually indicate a poor refinement model. Also
 check for unaccounted for twinning.   
#=============================================================================
# >>> Test for default SHELXL weighting scheme  
_085    0   10   10 2 A   0 0 0 1   
SHELXL Default Weighting Scheme is not Optimized     Please Check   

 The weighting scheme is found to be left at the SHELXL default. This
 default value is recommended for the preliminary structure refinement. It is
 uncommon that this unoptimized weight gives the best final refinement result.
#=============================================================================
# >>> Test for reasonable S value (too Low)  
_086  0.4  0.6  0.8 2 A   0 0 0 1   
Unsatisfactory S Value (Too Low or Not Given) .. $F Check   

 The Goodness-of-Fit value S should in general be close to 1 at the end of a
 refinement with a proper weighting scheme. If not, there might be significant
 unresolved problems with the refinement model or reflection data.
#=============================================================================
# >>> Test for reasonable S value (too High)  
_087  2.0  4.0  6.0 2 A   0 0 0 1   
Unsatisfactory S value (Too High) .............. $F Check   

 The Goodness-of-Fit value S should in general be close to 1 at the end of a
 refinement with a proper weighting scheme. If not, there might be significant
 unresolved problems with the refinement model or reflection data.
#=============================================================================
# >>> Test for reasonable data / parameter ratio  (centrosymmetric case)  
_088 10.0 12.5 16.7 3 A   0 0 1 0   
Poor Data / Parameter Ratio .................... $F Note

 The data/parameter ratio should in general be higher than 10 for a quality 
 structure determination. This ratio can be improved by not refining
 C-H parameters other than riding on their carrier atom.
#=============================================================================
# >>> Test for reasonable data / parameter ratio (non-centro) (Zmax < 18)   
_089 13.5 18.0 25.0 3 A   0 0 1 0   
Poor Data / Parameter Ratio (Zmax < 18) ........ $F Note

 The data/parameter ratio should in general be higher than 7 for a quality  
 determination of a structure containing atoms with Z less than 18. This
 ratio can be improved by not refining C-H parameters other than riding on
 their carrier atom. 
 Note: The number of reflections used in this ratio is the number obtained  
 by Laue group averaging.   
#=============================================================================
# >>> Test for reasonable data / parameter ratio (non-centro) (ZMAX > 18)   
_090 12.5 16.5 25.0 3 A   0 0 1 0   
Poor Data / Parameter Ratio (Zmax > 18) ........ $F Note

 The data/parameter ratio should in general be higher than 8 for a quality  
 determination for a structure containing heavy atoms with ZMAX greater 
 than 17. This ratio can be improved by not refining C-H parameters other   
 than riding on their carrier atom.
 The number of reflections used for this ratio is the Laue averaged number
 of reflections. The validation criteria used are expected to be met with a
 dataset complete with a resolution sin(theta)/lambda .GE. 0.6 Ang-1. 
#=============================================================================
# >>> Test for 'No-wavelength given'
_091    0    0    0 1 A   1 0 0 0   
No Wavelength Found in CIF - 0.71073 Ang Assumed     Please Check   

 No Wavelength specification found in the CIF.  
#=============================================================================
# >>> Test for wavelength type [Cu, Ga, Mo, Ag, In Ka]
_092    0    0    0 4 A   0 0 0 1   
Check: Wavelength Given is not Cu,Ga,Mo,Ag,In Ka $F Ang.

 The wavelength, specified in the CIF, is not CuKa = 1.5418A, GaKa = 1.3414A,   
 MoKa = 0.71073A, AgKa = 0.56086A or InKa = 0.51359A radiation within a 
 tolerance of 0.0005A.  Valid exceptions are Kb, Neutron and Synchrotron data.  
#=============================================================================
# >>> Test for inconsistency 'mixed' versus 'no refined H positions'
_093    0    0    0 1 I   0 0 0 1   
No s.u.'s on H-positions, Refinement Reported as  $A Check  

 The 'mixed' type Hydrogen atom refinement is reported (SHELXL-97 default). 
 However, no Hydrogen atoms with freely refined positions are found in the  
 CIF. Likely, the value 'constr' or 'refU' for  
 '_refine_ls_hydrogen_treatment' will be more appropriate (e.g. when all
 Hydrogen atoms have been refined in the riding mode on their carrier atom).
#=============================================================================
# >>> Test for maximum/minimum residual density ratio   
_094  2.0  4.0  8.0 2 A   0 0 1 0   
Ratio of Maximum / Minimum Residual Density .... $F Report  

 The ratio of the maximum and minimum residual density excursions is
 unusual. This might indicate unaccounted for twinning or missing atoms 
 (e.g. associated with disordered solvent). 
#=============================================================================
# >>> Test for residual density maximum given [0,1] 
_095    0    0    0 1 A   1 0 0 0   
No Residual Density Maximum Given ..............     Please Do !

 No residual electron density maximum given in CIF. 
#=============================================================================
# >>> Test for residual density minimum given [0,1] 
_096    0    0    0 1 A   1 0 0 0   
No Residual Density Minimum Given ..............     Please Do !

 No residual electron density minimum given in CIF. 
#=============================================================================
# >>> Test maximum residual density (reported)  
_097 0.75  1.0  2.0 2 A   0 0 1 0   
Large Reported Max.  (Positive) Residual Density $F eA-3

 A residual density maximum larger than expected is reported. This might be 
 caused by residual absorption artefacts, unaccounted for twinning, disorder,   
 wrongly assigned atom types, missing hydrogen atoms and other model errors.
#=============================================================================
# >>> Test for minimum residual density (reported)  
_098 0.75  1.0  2.0 2 A   0 0 1 0   
Large Reported Min.  (Negative) Residual Density $F eA-3

 A residual density minimum larger than expected is reported. This might be 
 caused by residual absorption artefacts, disorder, wrongly assigned atom   
 types and other model errors.  
#=============================================================================
# >>> Test for minimum residual density greater zero [0, 1] 
_099  0.0  0.0  0.0 1 A   0 0 0 1   
Minimum (Negative) Residual Density .GE. 0 !!... $F eA-3

 Likely interchanged maximum and minimum values. Alternatively, the minimum
 residual density has the (unlikely) value zero.  
#==========================================================================
# >>> Report non-integer reported Z-value in CIF
_100    0    0    0 5 A   0 0 0 1
A Non-Integer Z value Reported in the CIF ...... $F Check  

 The norm is integer. The CIF-definition for _cell_formula_units_Z 
 specifies Z values as 1 -> infinity. SHELXL may report in certain cases a
 real number (E.g. Z = 0.67). In such a case, check whether really more
 decimals are intended and edit accordingly, i.e. 0.67 => 0.66667.
#==========================================================================
# >>> Test for insufficient digits for special position  1/3 & 2/3 in x-coord.  
_101    0    0   10 2 A   1 0 0 0   
Limited Precision x-Coordinate $A For ...  $B Check 

 Fractions of the type (+/-)1/3 and (+/-)2/3 for the positional parameters of   
 atoms in special positions should be provided with sufficient digits.  
 (i.e. 0.66667 and 0.33333). Check whether exact 1/3 etc. is intended.  
#=============================================================================
# >>> Test for insufficient digits for special position 1/3 & 2/3 in y-coord.   
_102    0    0   10 2 A   1 0 0 0   
Limited Precision y-Coordinate $A For ...  $B Check 

 Fractions of the type (+/-)1/3 and (+/-)2/3 for the positional parameters of   
 atoms in special positions should be provided with sufficient digits.  
 (i.e. 0.66667 and 0.33333). Check whether exact 1/3 etc. is intended.  
#=============================================================================
# >>> Test for insufficient digits for special position 1/3 & 2/3 in z-coord.   
_103    0    0   10 2 A   1 0 0 0   
Limited Precision z-Coordinate $A For ...  $B Check 

 Fractions of the type (+/-)1/3 and i(+/-)2/3 for the positional parameters of  
 atoms in special positions should be provided with sufficient digits.  
 (i.e. 0.66667 and 0.33333). Check whether exact 1/3 etc. is intended.  
#=============================================================================
# >>> Test for additional translational symmetry [0, 1]        
_104    0    0    0 1 A   0 0 0 1   
The Reported Crystal System is Inconsistent with  $A Check  

 Check the reported crystal system against the reported space group.
 Alternatively, no crystal system was reported. 
#=============================================================================
# >>> Test for inconsistent reported wavelengths in CIF and .res file 
_105    0    1    2 1 A   0 0 0 1
CIF and RES reported wavelengths inconsistent ..          ? Check
    
 The wavelengths reported in CIF format and on the CELL record in the embedded
 RES file should be identical. 
#=============================================================================
# >>> Test validity of inversion twinning operation 
_107    0    0   99 2 A   0 1 0 0   
Twinning Matrix Invalid in Centrosymmetric SPGR           ? Check   

 Inversion twinning is meaningless in centrosymmetric spacegroup.   
#=============================================================================
# >>> Test validity of the twinning operation   
_108    1    1    1 2 A   0 1 0 0   
Twinning Matrix is inverted Laue group operation          ? Check   

 The SHELXL TWIN instruction matrix corresponds to a symmetry operation of the  
 non-centrosymmetric Laue group of the crystal structure. This is not a valid   
 twin operation.
#=============================================================================
# >>> Test the twinning operation as alternate inversion twinning   
_109    1    1    1 2 A   0 1 0 0   
Twinning Matrix = Alternate Inversion Twinning .          ? Check   

 The SHELXL TWIN instruction matrix corresponds to an inverted 
 non-centrosymmetric pointgroup operation belonging to the corresponding 
 centrosymmetric Laue group. The reported twinning factor is actually the
 Flack x value. The close to zero CIF reported Flack parameter value is 
 meaningless.  Please re-refine with the TWIN instruction replaced by 'TWIN'
 (i.e. without numerical data).
#=============================================================================
# >>> Test for additional translational symmetry [0, 1] (ADDSYM) 
_110  0.5  0.5  999 2 A   0 0 0 1   
ADDSYM Detects Potential Lattice Translation ...          ? Check   

 Tests for missed symmetry are done with ADDSYM, an extended MISSYM (C) 
 clone. These tests warn for missed or possible higher (pseudo) symmetry in 
 the structural model (i.e. based on the coordinate data).  
 Close examination of the situation at hand is indicated in order to
 prove/disprove the issue (usually in combination with the reflection data).
 Report on potential (pseudo/real) lattice centering or cell halving.   
 Note: H-atoms and disordered atoms are not taken into account in the tests.
#=============================================================================
# >>> Test for additional centre of symmetry [0, 100] (ADDSYM)  
_111   90   95  100 2 A   0 0 0 1   
ADDSYM Detects New (Pseudo) Centre of Symmetry . $I %Fit

 Tests for missed symmetry are done with ADDSYM, an extended MISSYM (C) 
 clone. These tests warn for missed or possible higher (pseudo) symmetry in 
 the structural model (i.e. based on the coordinate data). Close examination
 of the situation at hand with PLATON/ADDSYM is indicated in order to prove/
 disprove the issue (usually in combination with the reflection data). 
 This ALERT reports on a potential additional (pseudo/real) inversion centre.   
 A pseudo-centre may be incompatible with existing symmetry elements.   
 Chiral molecules are incompatible with an inversion centre.
 Note: H-atoms and disordered atoms are not taken into account in the test. 
#=============================================================================
# >>> Test for additional symmetry [0, 1] (ADDSYM)  
_112   50   95  100 2 A   0 0 0 1   
ADDSYM Detects New (Pseudo) Symm. Elem $A $I %Fit   

 Tests for missed symmetry are done with ADDSYM, an extended MISSYM (C) 
 clone. These tests warn for missed or possible higher (pseudo) symmetry in 
 the structural model (i.e. based on the coordinate data). Close examination
 of the situation at hand is indicated in order to prove/disprove the issue 
 (usually in combination with the reflection data). This ALERT reports on
 potential additional (pseudo/real) rotation axes and mirrors.   
 In addition, (pseudo/real) lattice centering/translations are reported as  
 A, B, C, I, X, Y, Z, S. (Here S stands for special and not covered by the  
 preceding types). Full details on the situation at hand should be gleaned  
 from an actual PLATON/ADDSYM run.  
 Note: Atom types are treated in this test as EQUAL for structures with less
 than 250 atoms in the asymmetric unit in order to detect cases of misassigned
 atom types.  
 Chiral molecules are incompatible with an inversion centre or (glide)planes.   
 Note: H-atoms and disordered atoms are not taken into account in the tests.
#=============================================================================
# >>> Report New space-group suggested by ADDSYM
_113   90   95  100 2 A   0 0 0 1   
ADDSYM Suggests Possible Pseudo/New  Space Group  $A Check  

 Tests for missed symmetry are done with ADDSYM, an extended MISSYM (C) 
 clone. These tests warn for missed or possible higher (pseudo) symmetry in 
 the structural model (i.e. based on the coordinate data). Close examination
 of the situation at hand is indicated in order to prove/disprove the issue 
 (usually in combination with the reflection data). 
 Chiral molecules are incompatible with an inversion centre or (glide)planes.   
 For an example of reported pseudo-symmetry see I.A.Guzei et al, (2002).
 Acta Cryst. C58, m141-m143.
 Note: H-atoms and disordered atoms (i.e. atoms with population less
 than 1.0) are not taken into account in the tests. This may artificially   
 lead to a symmetry higher than the actual one. 
 Note: Atoms are treated as having the same atom type in order to catch 
 certain types of disorder or incorrect atom type assignment.   
#=============================================================================
# >>> Report on ADDSYM problem  
_114    0    2    2 2 A   0 0 0 1   
ADDSYM Could not (Re)Construct Proper Spacegroup     Please Check   

 ADDSYM has problems to reconstruct a space group from the symmetry operation
 found in the symmetry expanded coordinate set. The reason being either
 intricate additionally detected pseudo-symmetry or serious errors in the data
 set.   
#=============================================================================
# >>> Test for non-crystallographic centre of symmetry [0, 100] 
_115   50  100  100 5 A   0 0 0 1   
ADDSYM Detects Noncrystallographic Inversion ...$I% Check   

 Tests for missed symmetry are done with ADDSYM, an expanded MISSYM (C) 
 clone. This ALERT reports on local inversion symmetry, not compatible  
 with the reported space-group symmetry.
 Note: H-atoms and disordered atoms are not taken into account in the test. 
#=============================================================================
# >>> Report implemented (pseudo) lattice translation
_116    0    1    2 2 A   0 0 0 1
ADDSYM Included (Pseudo) Lattice Translation ...     Please Check
 
 A (Pseudo) Lattice translation was detected and implemented before the 
 current ADDSYM analysis. 
#=============================================================================
# >>> Report problem with symmetry operator syntax  
_119    0    0    0 1 A   0 0 0 1   
Problem with the Syntax of a Symmetry Operation.  $A Check  

 A symmetry operation should be specified in the CIF either without 
 spaces or between quotes.  
#=============================================================================
# >>> Test for consistent _symmetry_space_group_name_H-M and Symm Opp   
_120    0   10   10 1 A   0 0 0 1   
Reported $A Inconsistent with Explicit     $B Check 

 Space group symmetry should be provided in the CIF both explicitly with a  
 _symmetry_equiv_pos_as_xyz loop and implicitly with
 _symmetry_space_group_name-H-M.

 An unusual (non-standard) choice of origin may also raise this ALERT.  
 Please check and Explain.  
#=============================================================================
# >>> Test for valid _symmetry_space_group_name_H-M (+ aliases) 
_121    0   10   10 1 A   1 0 0 0   
Invalid _symmetry_space_group_name_H-M .........  $A Check  

 Symmetry in the CIF should be provided both explicitly with a  
 _symmetry_equiv_pos_as_xyz loop and implicitly with
 _symmetry_space_group_name_H-M.
 Test for valid _symmetry_space_group_name_H-M symbol.  
#=============================================================================
# >>> Test for ? _symmetry_space_group_name_H-M 
_122    0    0    0 1 A   1 0 0 0   
No _symmetry_space_group_name_H-M Given ........     Please Do !

 Symmetry in the CIF should be provided both explicitly with a  
 _symmetry_equiv_pos_as_xyz loop and implicitly with
 _symmetry_space_group_name_H-M.
 Test for missing (i.e. ?) _symmetry_space_group_name_H-M symbol.   
#=============================================================================
# >>> Test for interpretable space-group symmetry   
_123    0    0    0 1 A   1 0 0 0   
Uninterpretable or Inconsistent Space-Group Info     Please Check   

 Symmetry in the CIF should be provided in the CIF both explicitly with a   
 _symmetry_equiv_pos_as_xyz loop and implicitly with
 _symmetry_space_group_name_H-M or _symmetry_space_group_name_H-M_alt.  
 Test for uninterpretable or inconsistent Space group information.  
#=============================================================================
# >>> Test for _symmetry_equiv_pos_as_xyz present   
_124    0    0    0 1 A   1 0 0 0   
Uninterpretable or No _symmetry_equiv_pos_as_xyz          ? Check   

 Symmetry in the CIF should be provided in the CIF both explicitly with a   
 _symmetry_equiv_pos_as_xyz loop and implicitly with
 _symmetry_space_group_name_H-M.
 Test for uninterpretable or absent explicit symmetry records.  
#=============================================================================
# >>> Test for ? _symmetry_space_group_name_Hall
_125    0   10   10 4 I   1 0 0 0   
No '_symmetry_space_group_name_Hall' Given .....     Please Do !

 Optionally specify the Hall symbol. The Hall symbol provides an
 unambiguous definition of the space-group symmetry where the Hermann-  
 Mauguin symbol leaves room for alternative choices of the origin.  
 E.g. for space-group P21, the screw axis is in general taken to coincide   
 with the b-axis. However, sometimes it is chosen to be shifted by 1/4  
 in the c-axis direction to bring out the relation with P21/c. The Hall 
 symbols will be 'P 2yb' and 'P 2ybc' respectively. 

 Refer to: S.R.Hall, Space Group Notation with an Explicit Origin;  
           Acta Cryst. (1981), A37, 517-525.

       or: http://www.kristall.ethz.ch/LFK/software/sginfo/hall_symbols.html
#=============================================================================
# >>> Test for  _symmetry_space_group_name_Hall error   
_126    0   10   10 1 A   0 0 0 1   
Error in or Uninterpretable Hall Symbol  ....... $A Check  

 The reported Hall-symbol is found to be in error or uninterpretable.   

 Refer to: S.R.Hall, Space Group Notation with an Explicit Origin;  
           Acta Cryst. (1981), A37, 517-525.
       or: http://cci.lbl.gov/sginfo/hall_symbols.html
#=============================================================================
# >>> Test for  _symmetry_space_group_name_Hall consistency 
_127    0   10   10 1 A   0 0 0 1   
Implicit Hall Symbol  Inconsistent with Explicit $A Check 

 The reported Hall-symbol is not identical to the one internally tabulated
 for the space group as derived from the explicitly supplied symmetry
 operations. As an example, the Hall symbols '-P 2yn' and '-P 2yabc' both 
 correspond with space group 'P21/n'. Alternatively, no Hall-symbol could be
 derived by PLATON for the explicit set of symmetry operations. This may be
 the case when an unusual origin is chosen. 

 Refer to: S.R.Hall, Space Group Notation with an Explicit Origin;  
           Acta Cryst. (1981), A37, 517-525.
       or: http://cci.lbl.gov/sginfo/hall_symbols.html
#=============================================================================
# >>> Test for non-standard space_group settings
_128    0   10   10 4 A   0 0 0 1   
Alternate Setting for Input Space Group$A  $B Note  

 P21/n and I2/a etc. settings are often preferred over P21/c and C2/c when  
 that leads to a closer to 90 degrees beta angle.   
 Standard choice of origin is to be preferred. A non-standard origin choice 
 might be useful for for the comparison of related structures.  
#=============================================================================
# >>> Test for unusual non-standard Space group name
_129    0    0    0 4 A   0 0 0 1   
Unusual Space Group Specified ..................  $A Check  

 The reported space-group name is unusual.  
#=============================================================================
# >>> Test for cubic: a = b = c 
_130    0    0    0 1 A   0 1 0 0   
Cubic : a, b & c Dimensions Differ ...........       Please Check   

 Symmetry constraints on cell dimensions are checked.   
#=============================================================================
# >>> Test for cubic: alpha = beta = gamma = 90 
_131    0    0    0 1 A   0 1 0 0   
Cubic : alpha, beta and gamma should be 90 Deg Exact Please Check   

 Symmetry constraints on cell dimensions are checked.   
#=============================================================================
# >>> Test for trigonal/hexagonal : a = b   
_132    0    0    0 1 A   0 1 0 0   
Trigonal/Hexagonal a and b Differ ..............     Please Check   

 Symmetry constraints on cell dimensions are checked.   
#=============================================================================
# >>> Test for trigonal/hexagonal : alpha = beta = 90   
_133    0    0    0 1 A   0 1 0 0   
Trigonal/Hexagonal alpha and beta Should be 90 Deg   Please Check   

 Symmetry constraints on cell dimensions are checked.   
#=============================================================================
# >>> Test for trigonal/hexagonal : gamma = 120 
_134    0    0    0 1 A   0 1 0 0   
Trigonal/Hexagonal gamma Should be 120 Deg Exact     Please Check   

 Symmetry constraints on cell dimensions are checked.   
#=============================================================================
# >>> Test for tetragonal: a = b
_135    0    0    0 1 A   0 1 0 0   
Tetragonal: a and b Should be Equal ...........      Please Check   

 Symmetry constraints on cell dimensions are checked.   
#=============================================================================
# >>> Test for tetragonal: alpha = beta = gamma = 90
_136    0    0    0 1 A   0 1 0 0   
Tetragonal: alpha, beta & gamma Should be 90 Deg     Please Check   

 Symmetry constraints on cell dimensions are checked.   
#=============================================================================
# >>> Test for orthorhombic: alpha = beta = gamma = 90  
_137    0    0    0 1 A   0 1 0 0   
Orthorhombic: alpha, beta & gamma Should be 90 Deg   Please Check   

 Symmetry constraints on cell dimensions are checked.   
#=============================================================================
# >>> Test for monoclinic more than 1 angle off 90 degrees  
_138    0    0    0 1 A   0 1 0 0   
Monoclinic: More than one Angle Unequal 90.0 ...     Please Check   

 Symmetry constraints on cell dimensions are checked.   
#=============================================================================
# >>> Test for rhombohedral a = b = c   
_139    0    0    0 1 A   0 1 0 0   
Rhombohedral: a, b & c are not all Exactly Equal     Please Check   

 Symmetry constraints on cell dimensions are checked.   
#=============================================================================
# >>> Test for rhombohedral alpha = beta = gamma
_140    0    0    0 1 A   0 1 0 0   
Rhombohedral: alpha, beta & gamma are Not All Equal  Please Check   

 Symmetry constraints on cell dimensions are checked.   
#=============================================================================
#1>>> s.u. on a - axis small or missing 
_141    0   10   10 4 A   1 0 0 0   
s.u. on a - Axis Small or Missing .............. $F Ang.

 The s.u. on the a-axis is small or missing. The presence of s.u.'s (where  
 required) and value are checked. S.u.'s as given by the diffractometer 
 software are often much smaller then realistic.
#=============================================================================
#1>>> s.u. on b - axis small or missing 
_142    0   10   10 4 A   1 0 0 0   
s.u. on b - Axis Small or Missing .............. $F Ang.

 The s.u. on the b-axis is small or missing. The presence of s.u.'s (where  
 required) and value are checked. Su's as given by the diffractometer software
 are often much smaller then realistic.
#=============================================================================
#1>>> s.u. on c - axis small or missing 
_143    0   10   10 4 A   1 0 0 0   
s.u. on c - Axis Small or Missing .............. $F Ang.

 The s.u. on the c-axis is small or missing. The presence of s.u.'s (where  
 required) and value are checked. Su's as given by the diffractometer software
 are often much smaller then realistic.
#=============================================================================
#1>>> s.u. on alpha small or missing
_144    0   10   10 4 A   1 0 0 0   
s.u. on alpha    Small or Missing .............. $F Degree  

 The s.u. on alpha is small or missing. The presence of s.u.'s (where required) 
 and value are checked. Su's as given by the diffractometer software are often
 much smaller then realistic. 
#=============================================================================
#1>>> s.u. on beta  small or missing
_145    0   10   10 4 A   1 0 0 0   
s.u. on beta     Small or Missing .............. $F Degree  

 The s.u. on beta is small or missing. The presence of s.u.'s (where required)  
 and value are checked. Su's as given by the diffractometer software are often
 much smaller then realistic. 
#=============================================================================
#1>>> s.u. on gamma small or missing
_146    0   10   10 4 A   1 0 0 0   
s.u. on gamma    Small or Missing .............. $F Degree  

 The s.u. on gamma is small or missing. The presence of s.u.'s (where required) 
 and value are checked. Su's as given by the diffractometer software are
 often much smaller then realistic. 
#=============================================================================
#1>>> s.u. on symmetry restricted cell angle
_147    0   10   10 1 A   0 1 0 0   
s.u. on Symmetry Constrained Cell Angle(s) .....     Please Check   

 There should be no s.u. on symmetry constrained cell angles.   
 Example: No s.u. on alpha, beta and gamma for orthorhombic symmetry.   
#=============================================================================
#1>>> s.u. on a,b, or c - axis too large
_148    0   10   10 3 A   0 1 0 0   
s.u. on the $A - Axis is (Too) Large .... $F Ang.   

 The s.u. on the reported -axis is unexpectedly large.  
#=============================================================================
#1>>> s.u. on alpha, beta or gamma too large
_149 0.10 0.20   10 3 A   0 1 0 0   
s.u. on the $A Angle is Too Large ....... $F Degree 

 The s.u. on the reported angle is too large.   
#=============================================================================
#1>>> Check reported unit cell Volume value 
_150 0.5   1.0  1.0 1 A   1 0 0 0   
Volume as Calculated Differs from that Given ... $F Ang-3   

 An ALERT is issued when the reported unit cell volume differs significantly
 from the volume calculated on the basis of the supplied cell dimensions.   
#=============================================================================
# >>> Check for s.u. on volume  
_151    0   10   10 1 A   1 0 0 0   
No s.u. (esd) Given on Volume ..................     Please Do !

 Missing s.u. on cell volume.   
#=============================================================================
# >>> Check for consistency of s.u. on volume and cell parameters   
_152    1   99   99 1 I   0 0 0 0   
The Supplied and Calc. Volume s.u. Differ by ... $I Units   

 Some software packages calculate Volume s.u.'s incorrectly. The correct
 formula  for triclinic, monoclinic and orthorhombic systems
 (based on the propagation of error expression) may be found in:

 M. Nardelli, Computer & Chemistry, (1983), 7, 95-98.   
 or 
 C. Giacovazzo ed. in 'Fundamentals of Crystallography', Second Edition,
 Oxford University Press, 2003,  p135.  

 Also note that several cell parameters for higher symmetry cells are no
 longer independent. S.u. calculations need special treatment in those cases.   
#=============================================================================
# >>> test for equal axial s.u.'s   
_153    0   10   10 1 I   0 0 0 1   
The s.u.'s on the Cell Axes   are Equal ..(Note) $F Ang.

 The reported cell axes s.u.'s are reported equal. Please check whether 
 this is correct or a software default value.   
#=============================================================================
# >>> test for equal cell angle s.u.'s  
_154    0   10   10 1 I   0 0 0 1   
The s.u.'s on the Cell Angles are Equal ..(Note) $F Degree  

 The reported cell angle s.u.'s are reported equal. Please check whether
 this is correct or a software default value.   
#=============================================================================
# >>> Check for reduced cell aP 
_155    0   10   10 4 A   0 0 0 1   
The Triclinic Unitcell is NOT Reduced ..........     Please Do !

 Unless for special reasons related to the structure/content, a unit-cell and   
 structure is best reported with reference to the Niggli Reduced Cell. This
 ALERT may originate also from a failure to order the axes from small to large
 dimension.
#=============================================================================
# >>> Check for non-standard axial order
_156    0   10   10 4 A   0 0 0 1   
Axial System Input Cell not Standard ...........     Please Do !

 The axial order should be from small to large in the triclinic cell.   
#=============================================================================
# >>> Check for non-standard monoclinic beta angle < 90 Degrees. 
_157  0.0  10.  10. 4 A   0 0 0 1   
Non-standard Monoclinic Beta Angle less 90 Deg   $F Degree  

 By convention, the Monoclinic beta angle is always chosen to be larger than
 90.0 Degrees. A trivial transformation (1 0 0/0 -1 0/0 0 -1) should be 
 applied to the data.   
#=============================================================================
# >>> Check for standard reduced cell   
_158    0   10   10 4 A   0 0 0 1   
The Input Unitcell is NOT Standard/Reduced .....     Please Check   

 Unless for special reasons related to the structure/content, a unit-cell and   
 structure is best reported with reference to the Niggli Reduced Cell.  
#=============================================================================
# >>> Check beta-angle value for monoclinic c   
_159    0    0    0 1 A   0 1 0 0   
The Beta Angle Deviates from 90 for Monoclinic-c     Please Check   

 Only the Gamma angle may have a value not equal to 90 degrees. 
#=============================================================================
# >>> Missing x-coordinate s.u. 
_161    0   10   10 4 A   0 0 0 1   
Missing or Zero s.u. (esd) on x-coordinate for .  $A Check  

 Missing or Zero s.u. (esd) on x-coordinate.

 Positional parameters for all non-hydrogen atoms in general positions are  
 checked for the presence of a non-zero s.u. on them. This includes 
 parameters fixed to fix the origin in polar space-groups which is no longer
 necessary when refinement is done with modern programs (e.g. SHELXL, XTAL).
#=============================================================================
# >>> Missing y-coordinate s.u. 
_162    0   10   10 4 A   0 0 0 1   
Missing or Zero s.u. (esd) on y-coordinate for .  $A Check  

 Missing or Zero s.u. (esd) on y-coordinate.

 Positional parameters for all non-hydrogen atoms in general positions are  
 checked for the presence of a non-zero s.u. on them. This includes 
 parameters fixed to fix the origin in polar space-groups (e.g. P21) which  
 is no longer necessary when refinement is done with modern programs
 (e.g. SHELXL, XTAL).   
#=============================================================================
# >>> Missing z-coordinate s.u. 
_163    0   10   10 4 A   0 0 0 1   
Missing or Zero s.u. (esd) on z-coordinate for .  $A Check  

 Missing or Zero s.u. (esd) on z-coordinate.

 Positional parameters for all non-hydrogen atoms in general positions are  
 checked for the presence of a non-zero s.u. on them. This includes 
 parameters fixed to fix the origin in polar space-groups (e.g. P41) which  
 is no longer necessary when refinement is done with modern programs
 (e.g. SHELXL, XTAL).   
#=============================================================================
# >>> Check for refined C-H H-atoms 
_164    0   10   10 4 A   0 0 1 0   
Nr. of Refined C-H H-Atoms in Heavy-Atom Struct. $I Note

 Warning: Refined C-H H-atoms in heavy-atom structure (i.e. containing an   
 element beyond element #18). Such H-atoms are in general better refined
 at calculated positions riding on the atoms they are attached to. A
 better data over parameter ratio will be achieved. 
#=============================================================================
# >>> Check for R-flagged non-H-atoms   
_165    0   10   10 3 A   0 0 0 1   
Nr. of Status R-Flagged Non-Hydrogen Atoms ..... $I Note

 Report on restrained (riding) Non-Hydrogen atoms. Note: This may lead to   
 non meaningfull bond and angle s.u.'s (ALERTS _751, _752). 
 R-flagged atoms may arise unintentional being caused by an "AFIX 0" line   
 being missing in a shelxl.ins file (SHELXL-97 refinement). 
 Alternatively, the number of refined parameters may have been limited  
 deliberately (e.g. by refinement of C-F with fixed known geometry, 
 similar to C-H) in order to keep the data/parameter ratio acceptable.  
#=============================================================================
# >>> Check for calc flagged atoms with s.u.'s on coordinates   
_166    0   10   10 4 A   0 0 0 1   
S.U's Given on Coordinates for Calc-flagged ....  $A Note   

 Calc-flagged atoms are not supposed to carry s.u.'s on their coordinates.  
#=============================================================================
# >>> Test DANG restraint value in CIF-embedded .res file
_167    0    0    0 3 A   0 0 1 0 
A Non-default DANG Restraint Value has been used $F Report

 SHELXL applies a default effective standard deviation value of 0.04 Ang for
 the DANG restraints. The use of a much stronger restraint, with a lower
 value of those parameters, may hide serious problems with a structure.
#=============================================================================
# >>> Check for EXYZ record(s) in CIF-embedded .res file  
_168    0    0    0 4 A   0 0 0 1   
The CIF-Embedded .res File Contains EXYZ Records $I Report  

 The use of EXYZ record(s) in the SHELXL .res file should be documented in the  
 experimental section of the associated publication.
#=============================================================================
# >>> Check for AFIX 1 record(s) in CIF-embedded .res file 
_169    0    0    0 4 A   0 0 0 1   
The CIF-Embedded .res File Contains AFIX 1 Recds $I Report  

 The use of 'AFIX 1' record(s) in the SHELXL .res file should be documented in  
 the experimental section of the associated publication.
#=============================================================================
# >>> Check for sufficient data in in atom data loop
_170    0    0    0 4 A   0 0 0 1   
Insufficient Data in Coordinate Loop ...........  $A

 Insufficient data encountered in coordinate loop.  
 A possible cause might be the use of a SHELX style '=' continuation line.  
#=============================================================================
# >>> Check for EADP record(s) in CIF-embedded .res file  
_171    0    0    0 4 A   0 0 0 1   
The CIF-Embedded .res File Contains EADP Records $I Report  

 The use of EADP record(s) in the SHELXL .res file should be documented in the  
 experimental section of the associated publication.
#=============================================================================
# >>> Check for DFIX record(s) in CIF-embedded .res file  
_172    0    0    0 4 A   0 0 0 1   
The CIF-Embedded .res File Contains DFIX Records $I Report  

 The use of DFIX record(s) should be documented in the experimental section 
 of the associated publication. 
#=============================================================================
# >>> Check for DANG record(s) in CIF-embedded .res file  
_173    0    0    0 4 A   0 0 0 1   
The CIF-Embedded .res File Contains DANG Records $I Report  

 The use of DANG record(s) should be documented in the experimental section 
 of the associated publication. 
#=============================================================================
# >>> Check for FLAT record(s) in CIF-embedded .res file   
_174    0    0    0 4 A   0 0 0 1   
The CIF-Embedded .res File Contains FLAT Records $I Report  

 The use of FLAT record(s) should be documented in the experimental section 
 of the associated publication. 
#=============================================================================
# >>> Check for SAME record(s) in CIF-embedded .res file   
_175    0    0    0 4 A   0 0 0 1   
The CIF-Embedded .res File Contains SAME Records $I Report  

 The use of SAME record(s) in the SHELXL .res file should be documented in the  
 experimental section of the associated publication.
#=============================================================================
# >>> Check for SADI record(s) in CIF-embedded .res file  
_176    0    0    0 4 A   0 0 0 1   
The CIF-Embedded .res File Contains SADI Records $I Report  

 The use of SADI record(s) in the SHELXL .res file should be documented in the  
 experimental section of the associated publication.
#=============================================================================
# >>> Check for DELU record(s) in CIF-embedded .res file   
_177    0    0    0 4 A   0 0 0 1   
The CIF-Embedded .res File Contains DELU Records $I Report  

 The use of DELU record(s) in the SHELXL .res file should be documented in the  
 experimental section of the associated publication.
#=============================================================================
# >>> Check for SIMU record(s) in CIF-embedded .res file  
_178    0    0    0 4 A   0 0 0 1   
The CIF-Embedded .res File Contains SIMU Records $I Report  

 The use of SIMU record(s) in the SHELXL .res file should be documented in the  
 experimental section of the associated publication.
#=============================================================================
# >>> Check for CHIV record(s) in CIF-embedded .res file  
_179    0    0    0 4 A   0 0 0 1   
The CIF-Embedded .res File Contains CHIV Records $I Report  

 The use of CHIV record(s) in the SHELXL .res file should be documented in the  
 experimental section of the associated publication.
#=============================================================================
# >>> Check rounding of cell axes and angles
_180    0    0    0 4 I   0 1 0 0   
Check Cell Rounding: # of Values Ending with 0 = $I Note

 It is unusual that more cell parameters end with a zero and the s.u. is 10.
 This problem might be caused by the specification of insufficient  
 'meaningful' digits as compared to the reported s.u.   

 see also: W.Clegg, Acta Cryst. (2003) E59, e2-e5.  
#=============================================================================
# >>> Check for all angles exactly 90 degrees in monoclinic 
_181    0    0    2 1 A   1 0 0 0   
All Angles Exactly 90 Degrees in Monoclinic Cell     Please Check   

 One of the angles in a monoclinic cell is expected to be not exactly 90
 degrees.   
#=============================================================================
# >>> Check for at least one s.u. greater than zero in monoclinic   
_182    0    0    2 1 A   1 0 0 0   
All Angles with zero s.u. in Monoclinic Cell ...     Please Check   

 One angle should have an s.u. greater than zero in a monoclinic cell.  
#=============================================================================
# >>> Check for _cell_measured_reflns_used value reported   
_183    0    0    0 1 A   1 0 0 0   
Missing _cell_measurement_reflns_used Value ....     Please Do !

 Please supply the value for _cell_measurement_reflns_used. 
#=============================================================================
# >>> Check for _cell_measured_theta_min value reported 
_184    0    0    0 1 A   1 0 0 0   
Missing _cell_measurement_theta_min Value ......     Please Do !

 Please supply the value for _cell_measurement_theta_min.   
#=============================================================================
# >>> Check for _cell_measured_theta_max value reported 
_185    0    0    0 1 A   1 0 0 0   
Missing _cell_measurement_theta_max Value ......     Please Do !

 Please supply the value for _cell_measurement_theta_max.   
#=============================================================================
# >>> Check for ISOR record(s) in CIF-embedded .res file  
_186    0    0    0 4 A   0 0 0 1   
The CIF-Embedded .res File Contains ISOR Records $I Report  

 The use of ISOR record(s) in the SHELXL .res file should be documented in the  
 experimental section of the associated publication.
#=============================================================================
# >>> Check for RIGU record(s) in CIF-embedded .res file  
_187    0    0    0 4 A   0 0 0 1   
The CIF-Embedded .res File Contains RIGU Records $I Report  

 The use of RIGU record(s) in the SHELXL .res file should be documented in the  
 experimental section of the associated publication.
#=============================================================================
# >>> Test SIMU restraint value in CIF-embedded .res file
_188    0    0    0 3 A   0 0 1  
A Non-default SIMU Restraint Value has been used $F Report

 SHELXL applies a default effective standard deviation value of 0.04 for the
 SIMU restraint. The use of a much stronger restraint with a lower value of 
 that parameter may hide serious problems with a structure such as wrong atom
 type assignments.   
#=============================================================================
# >>> Test SAME restraint value in CIF-embedded .res file
_189    0    0    0 3 A   0 0 1 0 
A Non-default SAME Restraint Value for $A $F Report

 SHELXL applies a default effective standard deviation value of 0.02 Ang for
 the SAME 1,2 or 1,3 bond restraints. The use of a much stronger restraint,
 with a lower value of those parameters, may hide serious problems with a
 structure.
#=============================================================================
# >>> Test RIGU restraint value in CIF-embedded .res file
_190    0    0    0 3 A   0 0 1 0
A Non-default RIGU Restraint Value for $A $F Report

 SHELXL applies a default effective standard deviation value of 0.004 for the
 RIGU restraint. The use of a much stronger restraint with a lower value of
 that parameter may hide serious problems with a structure such as wrong atom
 type assignments.
#=============================================================================
# >>> Test SADI restraint value in CIF-embedded .res file
_191    0    0    0 3 A   0 0 1 0 
A Non-default SADI Restraint Value has been used $F Report

 SHELXL applies a default effective standard deviation value of 0.02 Ang for
 the SADI bond restraints. The use of a much stronger restraint, with a lower
 value of those parameters, may hide serious problems with a structure.
#=============================================================================
# >>> Test DELU restraint value in CIF-embedded .res file
_192    0    0    0 3 A   0 0 1 0 
A Non-default DELU Restraint Value for $A $F Report

 SHELXL applies a default effective standard deviation value of 0.01 Ang for
 the DELU restraints. The use of a much stronger restraint, with a lower
 value of those parameters, may hide serious problems with a structure.
#=============================================================================
# >>> Test for consistency of cell & diffraction temperatures   
_193    0    5   10 1 I   0 1 0 0   
Cell and Diffraction Temperatures Differ by .... $I Degree  

 The reported _cell_measurement_temperature deviates from the reported  
 _diffrn_ambient_temperature value. The relevant set of cell parameter values
 are those at the datacollection temperature (i.e. ambient temperature at the 
 crystal) because the derived geometry parameter values will be correct and 
 meaningfull only when those cell paarameter values are used. When relevant,
 cell parameter values at temperatures differing from the
 _diffrn_ambient_temperature are best archived as comment value under 
 _cell_special_details.   
#=============================================================================
# >>> Report on non-default DEFS restraint values in CIF-embedded .res file
_194    0    0    0 3 A   0 0 1 0
A Non-default DEFS Restraint Value set $A $F Note!

 Non-default DEFS parameter values in CIF-Embedded .res file. 
 See SHELXL manual.
#=============================================================================
# >>> Test DFIX restraint value in CIF-embedded .res file
_195    0    0    0 3 A   0 0 1 0 
A Non-default DFIX Restraint Value has been used $F Report

 SHELXL applies a default effective standard deviation value of 0.02 Ang for
 the DFIX restraints. The use of a much stronger restraint, with a lower
 value of those parameters, may hide serious problems with a structure.
#=============================================================================
# >>> Test for measurement temperature not equal 293K and no TEMP record
_196    0    0  2.0 1 I   1 0 0 0
No TEMP record and _measurement_temperature .NE. $I Degree

 SHELXL places Hydrogen atoms at calculated positions with default distance
 values to their parent atoms depending on the temperature reported in the
 TEMP record. When the TEMP record is absent in the embedded .res file a 
 default temperature of 293K is assumed. An ALERT is issued when the CIF 
 reported _measurement_temperature differs from that value.
#=============================================================================
# >>> Test for specification of unit-cell measurement temperature
_197    0    0    0 1 I   1 0 0 0   
Missing _cell_measurement_temperature Datum ....     Please Add 

 Please specify the temperature (Kelvin) at which the unit-cell parameters  
 were determined. That temperature should be generally identical to the 
 temperature value specified with _diffrn_ambient_temperature (the temperature
 of the crystal during data-collection) in order to make sense when used in
 the calculation of derived geometry parameter values (i.e. bond distances,
 bond angles etc.).
#=============================================================================
# >>> Test for specification of datacollection temperature  
_198    0    0    0 1 A   1 0 0 0   
Missing _diffrn_ambient_temperature   Datum ....     Please Add 

 Please specify the temperature (Kelvin) at which the intensity data were   
 collected. The reported cell parameter values should be those at this 
 temperature to make sense of the derived geometry parameter values. 
#=============================================================================
# >>> Test for SHELXL roomtemperature Default   (unit unitcell dimensions)  
_199    0  1.0  2.0 1 I   0 0 0 1   
Reported _cell_measurement_temperature ..... (K) $I Check   

 The cell determination temperature is set in the CIF by default by SHELXL97
 to 293 K when the TEMP instruction is not used. The actual temperature is  
 likely either slightly or significantly (in case of a low temperature data 
 collection)  different. A likely erroneous temperature of 273K (0C) is 
 also flagged.  
#=============================================================================
# >>> Test for SHELXL roomtemperature Default (datacollection)  
_200    0  1.0  2.0 1 I   0 0 0 1   
Reported   _diffrn_ambient_temperature ..... (K) $I Check   

 The data collection temperature is set in the CIF by default by SHELXL97 to
 293 K if the TEMP instruction is not used. A likely erroneous temperature of   
 273K (0C) is also flagged. The actual temperature is likely either slightly
 or significantly (for a low temperature data collection) different.
#=============================================================================
# >>> Test for isotropic non-H atoms in main residue(s) 
_201    0    0   10 2 A   0 0 1 0   
Isotropic non-H Atoms in Main Residue(s) ....... $I Report  

 This test reports on non-hydrogen atoms that were refined with isotropic   
 displacement parameters only in the main residue. Such a practice is unusual   
 by modern standards and only needed for minor disorder modelling.  
#=============================================================================
# >>> Test for isotropic non-H atoms in anion ? or solvent ?
_202    0   50   50 3 A   0 0 1 0   
Isotropic non-H Atoms in Anion/Solvent ......... $I Check   

 This test reports on isotropically refined atoms in small moieties (usually
 anions or solvent).
#=============================================================================
# >>> Test for negative non-hydrogen U(iso) 
_203    0    0    0 2 A   0 0 1 0   
Negative Isotropic ADP for $A ........... $F Report 

 Isotropic U(iso) values are expected to have a positive value. 
#=============================================================================
# >>> Test for 'all-isotropic adp(s)
_210    0    0   10 3 A   0 0 1 0   
No Anisotropic ADP's Found in CIF ..............     Please Check   

 No anisotropically refined atoms in CIF ?  
#=============================================================================
# >>> Test for NPD ADP's  (1.0) in main residue(s)  
_211    0    0  0.5 2 A   0 0 1 0   
ADP of Atom $A is N.P.D. or (nearly) 2D .     Please Check  

 This test reports on non-positive definite (i.e. complex and unrealistic)  
 anisotropic displacement parameters in the main residue.   
#=============================================================================
# >>> Test for NPD ADP's in anion? & solvent ? [0, 1]   
_212    0  0.5   99 2 A   0 0 1 0   
ADP of Atom $A is N.P.D. or (nearly) 2D .     Please Check  

 This test reports on non-positive definite (i.e. complex and   
 unrealistic) anisotropic displacement parameters in an anion or solvent
 residue.   
#=============================================================================
# >>> Test ratio adp max/min in main residue(s) 
_213  3.0  4.0  5.0 2 A   0 0 1 0   
Atom $A       has ADP max/min Ratio ..... $F $B 

 The main axes values of the ADP(S) of the main residue(s) are determined and   
 ordered: U1 < U2 < U3. The value of SQRT(U3/U1) main axis ADP ratio (Angstrom  
 Units) is tested for the main residue(s). Large values may indicate unresolved 
 disorder. Oblate criterium: U3 - U2 < U2 - U1. Prolate otherwise.  
#=============================================================================
# >>> Test ratio adp max/min in anion ? or solvent ?
_214  4.0  5.0  6.0 2 A   0 0 1 0   
Atom $A (Anion/Solvent) ADP max/min Ratio $F $B 

 The main axes values of the ADP(S) of the minor residue(s) are determined and  
 ordered: U1 < U2 < U3. The value of SQRT(U3/U1) main axis ADP ratio (Angstrom  
 Units) is tested for the main residue(s). Large values may indicate unresolved 
 disorder. Oblate criterium: U3 - U2 < U2 - U1. Prolate otherwise.  
#=============================================================================
# >>> Test for unusual disordered atom ADP in main residue  
_215  3.0  4.0  5.0 3 I   0 0 1 0   
Disordered $A has ADP max/min Ratio ..... $F Note   

 The maximum and minimum main axis ADP ratio (Angstrom Units) is tested for 
 the main residue. Large values may indicate unresolved disorder.   
#=============================================================================
# >>> Test for unusual disordered atom ADP in minor residue 
_216  5.0  7.0  9.0 3 I   0 0 1 0   
Disordered $A (An/Solv) ADP max/min Ratio $F Note   

 The maximum and minimum main axis ADP ratio (Angstrom Units) is tested for 
 the minor residue(s). Large values may indicate unresolved disorder.   
#=============================================================================
# >>> Test for incomplete U(i,j) data  
_217  0.0  0.0  0.0 1 A   1 0 0 0   
Incomplete U(aniso) Data for ...................  $A Check  

 Check & Correct U(aniso) data for completeness etc.
 Do not use SHELX style '=' continuation line.  
#=============================================================================
# >>> Test for constrained U(i,j)'s
_218    0    2    2 3 A   1 0 0 0   
Constrained U(i,j) Components(s) for $A   $I Check  

 U(i,j) components have been constrained (i.e. without s.u.) in the refinement
#=============================================================================
# >>> Test Ueq(max)/Ueq(Min) range for non-H atoms in non-solvent   
_220  3.0  6.0 10.0 2 I   0 0 1 0   
NonSolvent   Resd$Aeq(max)/Ueq(min) Range $F Ratio  

 This test reports on a larger than usual U(eq) range for the specified 
 element type in the non-solvent/anion part of the structure.   
 Too high or too low Ueq's may be an indication for incorrectly 
 identified atomic species (i.e. O versus N).   
#=============================================================================
# >>> Test Ueq(max)/Ueq(Min) range for non-H atoms in solvent   
_221  4.0  8.0 12.0 2 A   0 0 1 0   
Solv./Anion  Resd$Aeq(max)/Ueq(min) Range $F Ratio  

 This test reports on a larger than usual U(eq) range for the non-hydrogen  
 atoms solvent/anion. Too high or too low Ueq's may be an indication for
 incorrectly identified atomic species (i.e. Br versus Ag). 
#=============================================================================
# >>> Test Uiso(max)/Uiso(Min) range for H atoms in non-solvent 
_222  4.0 10.0 99.9 3 A   0 0 1 0   
NonSolvent Resd$Aiso(max)/Uiso(min) Range $F Ratio  

 This test reports on a larger than usual range of U(eq) values for hydrogen
 atoms in the non-solvent/anion part of the structure.  

 Possible causes are:   

 1 - disorder, e.g. in t-butyl moieties.
 2 - poor data, not adequate for the refinement of individual displacement  
     parameters.
 3 - Misplaced hydrogen atoms (i.e. there is no density at the position 
     where one of the H-atoms is positioned).   
#=============================================================================
# >>> Test Ueq(max)/Ueq(Min) range for H atoms in solvent   
_223  4.0 10.0 99.9 4 A   0 0 1 0   
Solv./Anion  Resd$Aeq(max)/Ueq(min) Range $F Ratio  

 This test reports on large ranges in displacement parameters for hydrogen  
 atoms in the solvent/anion part of the structure.  
#=============================================================================
# >>> Test for difference in implicit and explicit U(eq)
_224 .002 .003 .005 1 A   0 0 1 0   
Ueq(Rep) and Ueq(Calc) Differ by$A Ang**2  $B Check 

 This test reports on a large difference between Ueq in the CIF and the Ueq 
 calculated from the 6 reported U(i,j) values.                            .
#=============================================================================
# >>> Hirshfeld rigid-bond test [Acta Cryst. (1976), A32, 239-244] 
_230  5.0  7.0 99.0 2 A   0 0 1 0   
Hirshfeld Test Diff for    $A--$B. $F s.u.  

 The components of the anisotropic displacement parameters along chemical   
 bonds are assumed to be equal in magnitude. Large differences might
 indicate contamination of these parameters with other (unresolved) effects 
 such as (substitutional) disorder, model or data errors and/or 
 over-refinement. Atomic sites assigned the wrong scattering type (e.g. Ag  
 versus Br) should generate 'problem signals' with this test. Data sets 
 corrected for absorption effects with DELREF techniques (e.g. DIFABS, SHELXA,  
 XABS2) often show large DELU values for bonds involving the heaviest atom. 

 Note: The original 'Hirshfeld-test' was defined in absolute terms (see 
 F.L.Hirshfeld, Acta Cryst. (1976). A32, 239-244). The current test is with 
 reference to the associated standard uncertainty.  
#=============================================================================
# >>> Hirshfeld rigid-bond test (Solvent) [Acta Cryst. (1976),A32,239-244] 
_231  5.0  9.0 99.0 4 A   0 0 1 0   
Hirshfeld Test (Solvent)   $A--$B. $F s.u.  

 The components of the anisotropic displacement parameters along chemical   
 bonds are assumed to be equal in magnitude. Large differences might
 indicate the contamination of these parameters with other (unresolved) effects 
 such as (substitutional) disorder, model or data errors and/or 
 over-refinement. Atomic sites assigned the wrong scattering type (e.g. Ag  
 versus Br) should generate 'problem signals' with this test. Data sets 
 corrected for absorption effects with DELREF techniques (e.g. DIFABS, SHELXA,  
 XABS2) often show large DELU values for bonds involving the heaviest atom. 
 Note: The original 'Hirshfeld-test' was defined in absolute terms (see 
 F.L.Hirshfeld, Acta Cryst. (1976). A32, 239-244). The current test is with 
 reference to the associated standard uncertainty.  
#=============================================================================
# >>> Hirshfeld rigid-bond test (M-X) [Acta Cryst. (1976),A32,239-244]
_232  5.0 10.0 99.0 2 A   0 0 1 0   
Hirshfeld Test Diff (M-X)  $A--$B. $F s.u.  

 The components of the anisotropic displacement parameters along chemical   
 bonds are assumed to be equal in magnitude. Large differences might
 indicate contamination of these parameters with other (unresolved) effects 
 such as (substitutional) disorder, model or data errors and/or 
 over-refinement. Atomic sites assigned the wrong scattering type (e.g. Ag  
 versus Br) should generate 'problem signals' with this test. Data sets 
 corrected for absorption effects with DELREF techniques (e.g. DIFABS, SHELXA,  
 XABS2) often show large DELU values for bonds involving the heaviest atom. 

 A special case are M-C=O type of systems that generally show significant   
 differences for the M-C bond. See D.Braga & T.F. Koetzle (1988), Acta Cryst.   
 B44, 151-155). 

 Note: The original 'Hirshfeld-test' was defined in absolute terms (see 
 F.L.Hirshfeld, Acta Cryst. (1976). A32, 239-244). The current test is with 
 reference to the associated standard uncertainty.  

 Note: The 'Hirshfeld-test' ALERTS are suppressed for polymeric or disordered 
 structures.
#=============================================================================
# >>> Hirshfeld rigid-bond test (M-X solvent) [Acta Cryst. (1976),A32,239-244]
_233 10.0 15.0 99.0 4 A   0 0 1 0   
Hirshfeld (M-X Solvent)    $A--$B. $F s.u.  

 The components of the anisotropic displacement parameters along chemical   
 bonds are assumed to be equal in magnitude. Large differences might
 indicate contamination of these parameters with other (unresolved) effects 
 such as (substitutional) disorder, model or data errors and/or 
 over-refinement. Atomic sites assigned the wrong scattering type (e.g. Ag  
 versus Br) should generate 'problem signals' with this test. Data sets 
 corrected for absorption effects with DELREF techniques (e.g. DIFABS, SHELXA,  
 XABS2) often show large DELU values for bonds involving the heaviest atom. 

 Note: The original 'Hirshfeld-test' was defined in absolute terms (see 
 F.L.Hirshfeld, Acta Cryst. (1976). A32, 239-244). The current test is with 
 reference to the associated standard uncertainty.  
#=============================================================================
# >>> Hirshfeld rigid-bond test [Acta Cryst. (1976),A32,239-244]  
_234 0.15 0.25  0.3 4 A   0 0 1 0   
Large Hirshfeld Difference $A--$B. $F Ang.  

 The components of the anisotropic displacement parameters along chemical   
 bonds are assumed to be equal in magnitude. Large differences might
 indicate contamination of these parameters with other (unresolved) effects 
 such as (substitutional) disorder, model or data errors and/or 
 over-refinement. Atomic sites assigned the wrong scattering type (e.g. Ag  
 versus Br) should generate 'problem signals' with this test. Data sets 
 corrected for absorption effects with DELREF techniques (e.g. DIFABS, SHELXA,  
 XABS2) often show large DELU values for bonds involving the heaviest atom. 

 Note: The original 'Hirshfeld-test' was defined in absolute terms (see 
 F.L. Hirshfeld, Acta Cryst. (1976). A32, 239-244). 
#=============================================================================
# >>> Test for unusually high U(eq) as compared with bonded neighbours   
_241 .015 0.05 0.15 2 A   0 0 1 0   
High   'MainMol' Ueq as Compared to Neighbors of  $A Check  

 The U(eq) value of an atom is compared with the average U(eq) for to   
 non-hydrogen atoms bonded to it. Large differences may indicate that the   
 wrong atom type was assigned (e.g. N instead of O).
#=============================================================================
# >>> Test for Unusually Low  U(eq) as compared with bonded neighbours   
_242 .015 0.05 0.15 2 A   0 0 1 0   
Low    'MainMol' Ueq as Compared to Neighbors of  $A Check  

 The U(eq) value of an atom is compared with the average U(eq) for  
 non-hydrogen atoms bonded to it. Large differences may indicate that the   
 wrong atom type was assigned (e.g. N instead of O). False alarms may   
 occur for terminal groups such as the t-butyl moiety.  
#=============================================================================
# >>> Test for unusually high solvent U(eq) as compared with bonded neighbours   
_243 .015 1.00 1.00 4 A   0 0 1 0   
High   'Solvent' Ueq as Compared to Neighbors of  $A Check  

 The U(eq) value of an atom in the solvent or ion is compared with the average  
 U(eq) for non-hydrogen atoms bonded to it. Large differences may indicate  
 that the wrong atom type was assigned (e.g. N instead of O).   
#=============================================================================
# >>> Test for unusually low solvent  U(eq) as compared with bonded neighbours   
_244 .015 1.00 1.00 4 A   0 0 1 0   
Low    'Solvent' Ueq as Compared to Neighbors of  $A Check  

 The U(eq) value of an atom in the solvent or ion is compared with the average  
 U(eq) for non-hydrogen atoms bonded to it. Large differences may indicate  
 that the wrong atom type was assigned (e.g. N instead of O). False alarms may  
 occur for terminal groups such as the t-butyl moiety.  
#=============================================================================
# >>> Test for unusually low H-U(eq) as compared with bonded atom   
_245 0.01 0.05 0.10 2 A   0 0 1 0   
U(iso) $A Smaller than U(eq) $B by $F Ang**2

 U(iso) of a hydrogen atom is generally expected to be greater than the 
 U(eq) of the non-hydrogen atom it is attached to.  
#=============================================================================
# >>> Test for unusual anisotropic average U(i,j)  
_250 2.00 4.00 9.00 2 A   0 0 1 0   
Large U3/U1 Ratio for <U(i,j)> Tensor($A) $F Note

 An average value of the U(i,j) tensor of the asymmetric unit of a residue  
 is calculated. An ALERT is generated when the corresponding main axis U3/U1
 ratio deviates significantly from 1.0. Large values of this ratio should be
 taken as an indication of possible systematic errors in the data or errors
 in the model. Visual inspection of an ORTEP plot will show that many  
 displacement ellipsoids have their major axis pointing in the same direction.  
#=============================================================================
# >>> Test for high average Ueq for residue 
_260 .100 0.30 1.00 2 A   0 0 3 0   
Large Average Ueq of Residue Including $A $F Check  

 A large average Ueq value for a residue may indicate refinement with a too 
 high (possibly fixed) population parameter value.  
#=============================================================================
# >>> Test for fixed partial occupancy sites 
_299    0    0    0 4 A   0 0 1 0   
Atom Site Occupancy Constrained at ............. $F Check  

 This site is expected to be fully occupied but has been constrained (e.g.  
 with a SHELXL FVAR variable) or fixed at a value less than 1.0. Please check   
 for incomplete (substitutional) disorder handling. 
#=============================================================================
# >>> Test for fixed partial occupancy  
_300    0    0    0 4 A   0 0 1 0   
Atom Site Occupancy of $A  Constrained at $F Check  

 This site is expected to be fully occupied but has been constrained (e.g.  
 with a SHELXL FVAR variable) or fixed at a value less than 1.0. Please check   
 for incomplete (substitutional) disorder handling. 
#=============================================================================
# >>> Test for main residue(s) disorder %   
_301    0    0    0 3 A   0 0 1 0   
Main Residue  Disorder ..............($A)$I% Note   

 Atom sites that are not fully occupied are counted. A large fraction of
 disordered atoms may be both a signal for serious structure analysis   
 problems or less reliable/interesting results. 
#=============================================================================
# >>> Test for (anion/solvent) disorder %   
_302    0    0    0 4 A   0 0 1 0   
Anion/Solvent/Minor-Residue Disorder ($A)$I% Note   

 Atom sites that are not fully occupied are counted.
#=============================================================================
# >>> Test for more than 1 connection to H-atoms 
_303    1    2    3 2 A   0 0 1 0   
Full Occupancy Atom $A with # Connections $F Check  

 Hydrogen atoms are generally connected to only one other atom. A hydrogen  
 atom between two oxygen atoms is a special case. Investigate whether this  
 hydrogen atom is better described with a disorder model with two partially 
 occupied sites. A difference map might show a double-well density. 
#=============================================================================
# >>> Test for non-integer number of atoms in residue   
_304    0    2    2 4 A   0 0 1 0   
Non-Integer Number of Atoms in ..... ($B) $F Check  

 A non-integer number of atoms has been found in a residue. 
#=============================================================================
# >>> Test for isolated H-atoms  
_305    0    0    0 2 A   0 0 1 0   
Isolated Hydrogen Atom   (Outside Bond Range ??)  $A Check  

 This test reports on hydrogen atoms that are not on bonding distance to any
 atom. This ALERT may indicate that the hydrogen atom refined to a  
 non-bonding position or needs a symmetry operation to bring it to bonding  
 distance. It also may indicate a problem with incompatible population  
 parameters (e.g. C - H with population 0.8 and 0.9 respectively).  
#=============================================================================
# >>> Test for isolated oxygen atoms  
_306    0    0    2 2 A   0 0 1 0   
Isolated Oxygen Atom (H-atoms Missing ?) .......  $A Check  

 This test reports on oxygen atoms that are not within bonding distance to  
 any other atom in the structure. A common reason may be that no hydrogen   
 atoms are given for a water molecule. Attempts should be made to locate
 those hydrogen atoms from a difference map.
#=============================================================================
# >>> Test for isolated metal atoms   
_307    0    0    0 2 A   0 0 1 0   
Isolated Metal Atom found in Structure (Unusual)  $A Check  

 This test reports on metal atoms that are not bonded or at coordination
 distance of other atoms. Isolated ions are very unusual (or non-existent ?)
#=============================================================================
# >>> Test for single bonded metal atoms
_308    0    0    0 2 A   0 0 1 0   
Single Bonded Metal Atom in Structure  (Unusual)  $A Check  

 This test reports on single bonded (coordinated) metal atoms/ions. This
 represents a very unusual situation. There are literature examples where such  
 a 'single bonded metal' was shown to be a halogen. 
#=============================================================================
# >>> Test for single bonded oxygen atoms   
_309    0   99   99 2 A   0 0 1 0   
Single Bonded Oxygen (C-O > 1.3 Ang) ...........  $A Check  

 Single bonded Oxygen with C-O > 1.3 Angstrom. Missing H-Atom ? Check   
#=============================================================================
# >>> Test for 'too close' (symmetry related) full weight atoms 
_310    0    0    0 2 A   0 0 1 0   
$A Deleted (Close to $B)  Dist ... $F Ang.  

 This test identifies (very) short contacts between atoms that only becomes 
 apparent after the application of symmetry on the primary coordinate set.  
#=============================================================================
# >>> Test for isolated disordered Oxygen Atoms   
_311    0   10   10 2 A   0 0 1 0   
Isolated Disordered Oxygen Atom (No H's ?) .....  $A Check  

 This test reports on oxygen atoms (not full weight) that are not within
 bonding distance to any other atom in the structure.   
 A common reason may be that no hydrogen atoms are given for a water molecule.  
#=============================================================================
# >>> Test for C=O-H geometry
_312    0 0.02 0.05 2 A   0 0 1 0   
Strange C-O-H Geometry (C-O  <   1.25 Ang) .....  $A Check  

 Strange C-O-H geometry with C-O  <   1.25 Angstrom detected. Misplaced 
 H-Atom ?   
#=============================================================================
# >>> Test for Oxygen with three covalent bonds  
_313    0    2    2 2 A   0 0 1 0   
Oxygen with Three Covalent Bonds (rare) ........  $A Check  

 Oxygen atom with three covalent bonds detected. Check for correct atom type
 assignment (e.g. N rather than O)  

 Note: Exceptions are H3O+ (Oximium or Hydroxonium) and 
                      H5O2+ (Hydronium or aqua-hydroxonium) species.
#=============================================================================
# >>> Test for metal-O-H angle of H2O   
_314    0    2    2 2 A   0 0 1 0   
Small Angle for H2O: Metal-$A-$B . $F Degree

 A water molecule coordinated to a metal is detected with an unusually small 
 value of the Metal-Oxygen-Hydrogen Angle.
#=============================================================================
# >>> Test for single bonded carbon atom
_315    0    0    2 2 A   0 0 1 0   
Singly Bonded Carbon Detected (H-atoms Missing).  $A Check  

 Check for missing H-atoms. 
#=============================================================================
# >>> Check for too many H's on C in C=N bond in main residue(s)
_316    0    0    0 2 A   0 0 1 0   
Too many H on C in C=N Moiety in Main Residue ..  $A Check  

 An sp3 hybridized C was detected as part of a C=N moiety. Only one 
 attached H atom in sp2 configuration is expected and not two.  
 In SHELXL terms this corresponds with an erroneous AFIX 23 rather than an  
 AFIX 43 type of H atom position generation and refinement. 
#=============================================================================
# >>> Check for too many H's on C in C=N bond in solvent/ion (s)
_317    0   10   10 2 A   0 0 1 0   
Too many H on C in C=N Moiety in Solvent/Ion ...  $A Check  

 An sp3 hybridized C was detected as part of a C=N moiety. Only one 
 attached H atom in sp2 configuration is expected and not two.  
 In SHELXL terms this corresponds with an erroneous AFIX 23 rather than an  
 AFIX 43 type of H atom position generation and refinement. 
#=============================================================================
# >>> Hybridisation problem on N in main residue(s) 
_318    0   99   99 2 A   0 0 1 0   
Hybridisation of $A in Main Residue .....     Please Check  

 The test attempts to assign one of three hybridisations to N atoms in main 
 residue: sp, sp2 or sp3 on the basis of the angles around N.   
 This ALERT may indicate a mis-assigned H atom position (e.g. an atom   
 placed in a sp2 position instead of sp3).  
#=============================================================================
# >>> Hybridisation problem on N in solvent/ion 
_319    0   99   99 2 A   0 0 1 0   
Hybridisation of $A in Solvent/Ion ......     Please Check  

 The test attempts to assign one of three hybridisations to N atoms in main 
 residue: sp, sp2 or sp3 on the basis of the angles around N.   
 This ALERT may indicate a mis-assigned H atom position (e.g. an atom   
 placed in a sp2 position instead of sp3).  
#=============================================================================
# >>> Hybridisation problem on C in main residue(s) 
_320    0   99   99 2 A   0 0 1 0   
Hybridisation of $A in Main Residue .....     Please Check  

 The test attempts to assign one of three hybridisations to C atoms in main 
 residue: sp, sp2 or sp3 on the basis of the angles around C. In this way,  
 missing H atoms or too many H-atoms on a carbon atom should be detected.   
#=============================================================================
# >>> Hybridisation problem on C in solvent/ion 
_321    0   99   99 2 A   0 0 1 0   
Hybridisation of $A in Solvent/Ion ......     Please Check  

 The test attempts to assign one of three hybridisations to C atoms in  
 solven/anion: sp, sp2 or sp3 on the basis of the angles around C. In this  
 way missing H atoms or too many H-atoms on a carbon atom should be detected.   
#=============================================================================
# >>> Hybridisation problem on non-C in main residue(s) 
_322    0   99   99 2 A   0 0 1 0   
Hybridisation of $A in Main Residue .....     Please Check  

 The test attempts to assign one of three hybridisations to a non-C atom in 
 the main residue: sp, sp2 or sp3 on the basis of the angles around the non-C
 atom. In this way, missing H atoms or too many H-atoms should be detected. 
#=============================================================================
# >>> Hybridisation problem on non-C in solvent/ion 
_323    0   99   99 2 A   0 0 1 0   
Hybridisation of $A in Solvent/Ion ......     Please Check  

 The test attempts to assign one of three hybridisations to a non-C atom in 
 the solvent/anion: sp, sp2 or sp3 on the basis of the angles around the
 non-C atom. In this way, missing H atoms or too many H-atoms should be 
 detected.  
#=============================================================================
# >>> Check for possibly missing H on coordinating X-N-X in main residue
_324    0   99   99 2 A   0 0 1 0   
Check for Possibly Missing H on Coordinating....  $A Check  

 Check for possibly missing Hydrogen atom on Nitrogen coordinating to a metal
 in the main residue.   
#=============================================================================
# >>> Check for possibly missing H on coordinating X-N-X in solvent/anion   
_325    0   99   99 2 A   0 0 1 0   
Check for Possibly Missing H on Coordinating....  $A Check  

 Check for possibly missing Hydrogen atom on Nitrogen coordinating to a metal
 in the solvent/anion.  
#=============================================================================
# >>> Check for possibly missing H on potentially sp3 Carbon
_326    0    0   99 2 A   0 0 1 0   
Possible Missing H on sp3? Carbon ..............  $A Check  

 Check for possibly missing Hydrogen atom on Carbon with sp3-like geometry  
 in the main residue.   
#=============================================================================
# >>> Check for possibly missing H on potentially sp3 Carbon
_327    0    0   99 2 A   0 0 1 0   
Possible Missing H on sp3? Carbon ..............  $A Check  

 Check for possibly missing Hydrogen atom on Carbon with sp3-like geometry  
 in the solvent/anion.  
#=============================================================================
# >>> Check for a possibly missing H on potentially sp3 phosphorus  
_328    0   99   99 4 A   0 0 1 0   
Possible Missing H on sp3? Phosphorus ..........  $A Check  

 Check for a possibly missing Hydrogen atom on Phosphorus with sp3-like 
 geometry.  
#=============================================================================
# >>> Check for unclear carbon atom hybridisation   
_329    0   99   99 4 A   0 0 1 0   
Carbon Atom Hybridisation Unclear for ..........  $A Check  

 The hybridisation of this calbon atom could not be established from the
 number of substituents and their geometry. Check for missing hydrogen atoms
 and/or poor geometry.  
#=============================================================================
# >>> Check for large average phenyl C-C bond distance value 
_330 0.01 0.02 0.03 2 A   0 0 1 0   
Large Aver Phenyl C-C Dist $A--$B. $F Ang.  

 The standard average C-C bond distance in a phenyl ring is 1.395 Angstrom. 
 The actual average ring distance may be larger than expected due to
 systematic errors in the cell dimensions (e.g. use of incorrect
 wavelength value for the determination of the cell parameter>> Check Average Phenyl C-C  
_331 0.02 0.03 0.04 2 A   0 0 1 0   
Small Aver Phenyl C-C Dist $A--$B. $F Ang.  

 The standard average C-C bond distance in a phenyl ring is 1.395 Angstrom. 
 The average ring distance may be smaller due to large thermal motion or
 incorrect cell dimensions. 
#=============================================================================
# >>> Check phenyl C-C bond distance range
_332 0.15 0.25 0.35 2 A   0 0 1 0   
Large Phenyl C-C Range     $A -$B. $F Ang.  

 The standard average C-C in a phenyl ring is 1.395 Angstrom. Bond distances
 in the ring are expected to vary only slightly due to thermal motion or
 substituent effects. Large deviations are likely due to data or model errors.  
#=============================================================================
# >>> Check for large <C-C> bond distance in multiple substituted phenyl ring
_333 0.03 0.06 0.09 2 A   0 0 1 0   
Large Aver C6-Ring C-C Dist $A-$B. $F Ang.  

 The standard average C-C bond distance in a flat six carbon atom containing
 aromatic ring is 1.395 Angstrom.   
 The actual average ring distance may be larger than expected due to
 substituents such as '=O', single bonds or systematic errors in the cell   
 dimensions (E.g. when the wrong wavelength is used in the derivation of
 the cell parameters).  
#=============================================================================
# >>> Check for small <C-C> bond distance in multiple substituted phenyl ring
_334 0.03 0.06 0.09 2 A   0 0 1 0   
Small <C-C> Benzene Dist.   $A-$B. $F Ang.  

 The standard average C-C bond distance in a phenyl ring is 1.395 Angstrom.
 The average ring distance may be smaller due to large thermal motion,  
 substituents such as '=O' or incorrect cell dimensions.
#=============================================================================
# >>> Check multiple substituted phenyl type C-C bond distance range 
_335 0.15 0.25 0.35 2 A   0 0 1 0   
Check Large C6 Ring C-C Range $A-$B$F Ang.  

 The standard average C-C bond distance in a benzene ring is 1.395 Angstrom.
 Bond distances in the ring are expected to vary only slightly when due to  
 substituent effects (exceptions include =O substituents). Large deviations 
 may indicate data or model errors. 
#=============================================================================
# >>> Check for unusual bond distance   
_336 0.0  2.0  2.0  2 A   0 0 1 0   
Long Bond Distance for ..... $A-$B $F Ang.  

 Check this bond distance.  
#=============================================================================
# >>> Check average torsion angle in cyclo-hexane ring  
_338 25.0 45.0 60.0 4 A   0 0 1 0   
Small Aver Tau in Cyclohexane $A-$B$F Degree

 Cyclohexane moieties should have be significantly puckered as measured by  
 the average torsion angle tau. Unresolved disorder generally results in
 flattened rings and elongated displacement ellipsoids. A disorder model
 should be included in the calculations.
#=============================================================================
# >>> Check bond precision for C-C in light atom structures (Z(max) < 20)   
_340 .004 0.01 0.05 3 A   0 0 1 0   
Low Bond Precision on  C-C Bonds ............... $F Ang.

 The average s.u. for X-Y bonds is tested (named bond-precision). X-Y will  
 generally be C-C bonds, unless there are none. In the last case the s.u.'s of  
 the lowest element numbers are considered (excluding hydrogen). There are  
 three test ranges: one for structures with the largest element Z < 20, one 
 for the largest Z in the range 20 to 39 and one for structures with Z(max) 40  
 or higher (_340, _341 and _342 respectively).  
#=============================================================================
# >>> Check bond precision for C-C in structures (19 < Z(max) < 40) 
_341 .006 .015 .075 3 A   0 0 1 0   
Low Bond Precision on  C-C Bonds ............... $F Ang.

 The average s.u. for X-Y bonds is tested (named bond-precision). X-Y will  
 generally be C-C bonds, unless there are none. In the last case the s.u.'s of  
 the lowest element numbers are considered (excluding hydrogen). There are  
 three test ranges: one for structures with the largest element Z < 20, one 
 for the largest Z in the range 20 to 39 and one for structures with Z(max) 40  
 or higher (_340, _341 and _342 respectively).  
#=============================================================================
# >>> Check bond precision for C-C in structures (Z(max) > 39)  
_342 .008 .020 .100 3 A   0 0 1 0   
Low Bond Precision on  C-C Bonds ............... $F Ang.

 The average s.u. for X-Y bonds is tested (named bond-precision). X-Y will  
 generally be C-C bonds, unless there are none. In the last case the s.u.'s of  
 the lowest element numbers are considered (excluding hydrogen). There are  
 three test ranges: one for structures with the largest element Z < 20, one 
 for the largest Z in the range 20 to 39 and one for structures with Z(max) 40  
 or higher (_340, _341 and _342 respectively).  
#=============================================================================
# >>> Hybridisation problem on C in main residue(s) 
_343    0    0    0 2 A   0 0 1 0   
Unusual $AAngle Range in Main Residue for  $B Check 

 The angle range is larger than usual for the tentatively assigned  
 hybridisation of the reported atom in the main residue.
#=============================================================================
# >>> Hybridisation problem on C in solvent/ion 
_344    0    0    0 2 A   0 0 1 0   
Unusual $A Angle Range in Solvent/Ion for  $B Check 

 The angle range is larger than usual for the tentatively assigned  
 hybridisation of the reported atom in the solven/anion.
#=============================================================================
# >>> Test for short C - H (Angstrom difference) XRAY: 0.96 NEUT 1.08   
_350 0.11  0.2  0.3 3 A   0 0 1 0   
Short  C-H (X0.96,N1.08A) $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc.  Default C-H = 0.96 Ang. (X-Ray) value from SHELXL.   
#=============================================================================
# >>> Test for long  C - H (Angstrom difference) XRAY: 0.96 NEUT 1.08   
_351 0.14  0.2  0.3 3 A   0 0 1 0   
Long   C-H (X0.96,N1.08A) $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc.  Default C-H = 0.96 Ang. (X-Ray) value from SHELXL.   
#=============================================================================
# >>> Test for short N - H (Angstrom difference) XRAY: 0.87 NEUT 1.009  
_352  0.1  0.2  0.3 3 A   0 0 1 0   
Short  N-H (X0.87,N1.01A) $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc.  Default N-H = 0.87 Ang. (X-Ray) value from SHELXL.   
#=============================================================================
# >>> Test for long  N - H (Angstrom difference) XRAY: 0.87 NEUT 1.009  
_353 0.13  0.2  0.3 3 A   0 0 1 0   
Long   N-H (N0.87,N1.01A) $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc.  Default N-H = 0.87 Ang. (X-Ray) value from SHELXL.   
#=============================================================================
# >>> Test for short O - H (Angstrom difference) XRAY: 0.82 NEUT 0.983  
_354  0.1  0.2  0.3 3 A   0 0 1 0   
Short  O-H (X0.82,N0.98A) $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc.  Default O-H = 0.82 Ang. (X-Ray) value from SHELXL.   
#=============================================================================
# >>> Test for long  O - H (Angstrom difference) XRAY: 0.82 NEUT 0.983  
_355 0.18 0.25  0.3 3 A   0 0 1 0   
Long   O-H (X0.82,N0.98A) $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc.  Default O-H = 0.82 Ang. (X-Ray) value from SHELXL.   
#=============================================================================
# >>> Test for short B-H distance in X-BH3 moiety   
_356 0.05 0.16 0.25 3 A   0 0 1 0   
Short   X-BH3      Distance $A -$B $F Ang.  

 A short B-H distance may be due to fixing that distance to a wrong value,  
 e.g. to that of the C-H distance in a CH3 group.   
#=============================================================================
# >>> Test for long B-H distance in X-BH3 moiety
_357 0.10 0.20 0.30 3 A   0 0 1 0   
Long    X-BH3      Distance $A -$B $F Ang.  

 Check the long reported B-H bond distance (B-H is expected to have a value 
 around 1.16 Ang in a X-BH3 group)
#=============================================================================
# >>> Test for short B-H distance in (X,Y,Z)-B-H moiety  
_358 0.05 0.16 0.25 3 A   0 0 1 0   
Short  (X,Y,Z)-B-H Distance $A -$B $F Ang.  

 A short B-H distance may be due to fixing that distance to a wrong value.,  
 e.g. to that of the C-H distance.   
#=============================================================================
# >>> Test for long B-H distance in (X,Y,Z)-B-H moiety
_359 0.10 0.20 0.30 3 A   0 0 1 0   
Long   (X,Y,Z)-B-H Distance $A -$B $F Ang.  

 Check the long reported B-H bond distance (B-H is expected to have a value 
 around 1.06 Ang in a (X,Y,Z)-B-H moiety).
#=============================================================================
# >>> Test for short C4 - C4 (Angstrom difference) XRAY: 1.54   
_360  0.1  0.2  0.3 2 A   0 0 1 0   
Short  C(sp3)-C(sp3) Bond $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc. Default C4-C4 = 1.54 Ang. (X-Ray) value from  
 Ladd & Palmer, Structure Determination by Xray Crystallography (1985). 
 Note:  
  - C4-C4 indicates a bond between atoms with 4 bonds each. 
#=============================================================================
# >>> Test for long  C4 - C4 (Angstrom difference) XRAY: 1.54   
_361  0.1  0.2  0.3 2 A   0 0 1 0   
Long   C(sp3)-C(sp3) Bond $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc. Default C4-C4 = 1.54 Ang. (X-Ray) value from  
 Ladd & Palmer, Structure Determination by Xray Crystallography (1985). 
 Note:  
  - C4-C4 indicates a bond between atoms with 4 bonds each. 
#=============================================================================
# >>> Test for short C4 - C3 (Angstrom difference) XRAY: 1.52   
_362  0.1  0.2  0.3 2 A   0 0 1 0   
Short  C(sp3)-C(sp2) Bond $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc. Default C4-C3 = 1.52 Ang. (X-Ray) value from  
 Ladd & Palmer, Structure Determination by Xray Crystallography (1985). 
 Note:  
  - C4-C3 indicates a bond between an atom with 4 bonds and one with 3 bonds.   
  - Conjugated systems may cause some 'false alarm' messages.   
#=============================================================================
# >>> Test for long  C4 - C3 (Angstrom difference) XRAY: 1.52   
_363  0.1  0.2  0.3 2 A   0 0 1 0   
Long   C(sp3)-C(sp2) Bond $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc. Default C4-C3 = 1.52 Ang. (X-Ray) value from  
 Ladd & Palmer, Structure Determination by Xray Crystallography (1985). 
 Note:  
  - C4-C3 indicates a bond between an atom with 4 bonds and one with 3 bonds.   
  - Conjugated systems may cause some 'false alarm' messages.   
#=============================================================================
# >>> Test for short C4 - C2 (Angstrom difference) XRAY: 1.46   
_364  0.1  0.2  0.3 2 A   0 0 1 0   
Short  C(sp3)-C(sp)  Bond $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc. Default C4-C2 = 1.46 Ang. (X-Ray) value from  
 Ladd & Palmer, Structure Determination by Xray Crystallography (1985). 
 Note:  
  - C4-C2 indicates a bond between an atom with 4 bonds and one with 2 bonds.   
  - Conjugated systems may cause some 'false alarm' messages.   
#=============================================================================
# >>> Test for long  C4 - C2 (Angstrom difference) XRAY: 1.46   
_365  0.1  0.2  0.3 2 A   0 0 1 0   
Long   C(sp3)-C(sp)  Bond $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc. Default C4-C2 = 1.46 Ang. (X-Ray) value from  
 Ladd & Palmer, Structure Determination by Xray Crystallography (1985). 
 Note:  
  - C4-C2 indicates a bond between an atom with 4 bonds and one with 2 bonds.   
  - Conjugated systems may cause some 'false alarm' messages.   
#=============================================================================
# >>> Test for short C? - C? (Angstrom difference) XRAY: 1.50   
_366 0.35  0.5  1.0 2 A   0 0 1 0   
Short? C(sp?)-C(sp?) Bond $A -$B . $F Ang.  

 The hybridisation of at least one carbon atom is not recognized.   
 Large deviations from generally accepted values for a C-C bond may indicate
 model problems, unresolved disorder, over_refinement etc. The C-C bond is  
 tested to be not shorter than 1.15 Angstrom.   
#=============================================================================
# >>> Test for long  C? - C? (Angstrom difference) XRAY: 1.50   
_367 0.05  0.2  0.3 2 A   0 0 1 0   
Long?  C(sp?)-C(sp?) Bond $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc. Default C?-C? = 1.50 Ang. (X-Ray) value from  
 Ladd & Palmer, Structure Determination by Xray Crystallography (1985). 
#=============================================================================
# >>> Test for short C3 - C3 (Angstrom difference) XRAY: 1.34   
_368  0.1  0.2  0.3 2 A   0 0 1 0   
Short  C(sp2)-C(sp2) Bond $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc. Default C3-C3 = 1.34 Ang. (X-Ray) value from  
 Ladd & Palmer, Structure Determination by Xray Crystallography (1985). 
 Note:  
  - C3-C3 indicates a bond between atoms with 3 bonds each. 
  - Conjugated systems may cause some 'false alarm' messages.   
#=============================================================================
# >>> Test for long  C3 - C3 (Angstrom difference) XRAY: 1.34   
_369 0.18 0.22  0.3 2 A   0 0 1 0   
Long   C(sp2)-C(sp2) Bond $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc.  Default C3-C3 = 1.34 Ang. (X-Ray) value from 
 Ladd & Palmer, Structure Determination by Xray Crystallography (1985). 
 Note:  
  - C3-C3 indicates a bond between atoms with 4 with 3 bonds each.  
  - Conjugated systems may cause some 'false alarm' messages.   
  - A notable exception is the C-C bond in -C(=O)-C(=O)- systems with an
    observed mean value of 1.54 Angstrom.   
#=============================================================================
# >>> Test for short C3 - C2 (Angstrom difference) XRAY: 1.31   
_370  0.1  0.2  0.3 2 A   0 0 1 0   
Short  C(sp2)-C(sp1) Bond $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc. Default C3-C2 = 1.31 Ang. (X-Ray) value from  
 Ladd & Palmer, Structure Determination by Xray Crystallography (1985). 
 Note:  
  - C3-C2 indicates a bond between an atom with 3 bonds and one with 2 bonds.   
  - Conjugated systems may cause some 'false alarm' messages.   
#=============================================================================
# >>> Test for long  C3 - C2 (Angstrom difference) XRAY: 1.31   
_371 0.1  0.2   0.3 2 A   0 0 1 0   
Long   C(sp2)-C(sp1) Bond $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc. Default C3-C2 = 1.31 Ang. (X-Ray) value from  
 Ladd & Palmer, Structure Determination by Xray Crystallography (1985). 
 Note:  
  - C3-C2 indicates a bond between an atom with 3 bonds and one with 2 bonds.   
  - Conjugated systems may cause some 'false alarm' messages.   
#=============================================================================
# >>> Test for short C2 - C2 (Angstrom difference) XRAY: 1.25   
_372  0.1  0.2  0.3 2 A   0 0 1 0   
Short  C(sp)-C(sp)   Bond $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc. Default C2-C2 = 1.25 Ang. (X-Ray) value from  
 Ladd & Palmer, Structure Determination by Xray Crystallography (1985). 
 Note:  
  - C2-C2 indicates a bond between atoms with 2 bonds each. 
  - Conjugated systems may cause some 'false alarm' messages.   
#=============================================================================
# >>> Test for long  C2 - C2 (Angstrom difference) XRAY: 1.25   
_373  0.1  0.2  0.3 2 A   0 0 1 0   
Long   C(sp)-C(sp)   Bond $A -$B . $F Ang.  

 Large deviations from generally accepted values may indicate model problems,   
 over refinement etc. Default C2-C2 = 1.25 Ang. (X-Ray) value from  
 Ladd & Palmer, Structure Determination by Xray Crystallography (1985). 
 Note:  
  - C2-C2 indicates a bond between atoms with 2 bonds each. 
  - Conjugated systems may cause some 'false alarm' messages.   
#=============================================================================
# >>> Test for long  N - N bond  (> 1.45 Angstrom)  
_374 0.05 0.15 0.25 2 A   0 0 1 0   
Long   N - N         Bond $A -$B . $F Ang.  

 Large deviations from generally observed bond distances may indicate model 
 problems, over-refinement etc. Check for wrong atom-type assignments.  
 For an example see: Acta Cryst. (2003) E59, m710-m712. 
#=============================================================================
# >>> Test for C-O-H with large C-O bond distance
_375    0 0.02 0.05 2 A   0 0 1 0   
Strange C-O-H Geometry (C-O  >   1.45 Ang) .....  $A Check  

 Strange C-O-H geometry with C-O  >   1.45 Angstrom detected.   
 Wrong Atom Type ?  
#=============================================================================
# >>> Test for incorrectly oriented methyl moiety   
_380  0.0 10.0 10.0 4 A   0 0 1 0   
Incorrectly? Oriented X(sp2)-Methyl Moiety .....  $A Check  

 This test alerts for possible incorrectly oriented CH3 moieties.   
 (E.g. AFIX 33 instead of AFIX 137 etc. within the SHELXL realm).
#=============================================================================
# >>> Test methyl moiety X-C-H bond angle   
_390  6.5  9.5 50.0 3 A   0 0 1 0   
Deviating Methyl $A X-C-H Bond Angle .... $I Degree 

 Unusual Methyl Moiety X-C-H Angle (Ideally 109 Degrees for 4-bonded C).
#=============================================================================
# >>> Test methyl moiety H-C-H bond angle   
_391  7.5  9.5 50.0 3 A   0 0 1 0   
Deviating Methyl $A H-C-H Bond Angle .... $I Degree 

 Unusual Methyl Moiety H-C-H Angle (ideally 109 Degrees).   
#=============================================================================
# >>> Test general X-O-Y angle value
_395 10.0 180. 180. 2 A   0 0 0 1   
Deviating $BAngle From 120 for $A. $F Degree

 The X-O-Y angle value differs from the common ~120.0 Degrees.  
#=============================================================================
# >>> Test Si-O-Si angle value  
_396 10.0 180. 180. 2 A   0 0 0 1   
Deviating $BAngle From 150 for $A. $F Degree

 The Si-O-Si angle value differs from the common ~150.0 Degrees.
#=============================================================================
# >>> Test B-O-B angle value
_397 10.0 180. 180. 2 A   0 0 0 1   
Deviating $B Angle From 120 for $A $F Degree

 The B-O-B angle differs significantly from 120.0 degrees.  
 This is just a notice: B-O-B angles vary widely depending on what is bonded
 to the Boron atoms.
#=============================================================================
# >>> Test C-O-C angle value
_398 10.0 180. 180. 2 A   0 0 0 1   
Deviating $BAngle From 120 for $A. $F Degree

 The C-O-C angle value differs from the common ~120.0 Degrees.  
#=============================================================================
# >>> Test for short non-bonding intra H..H contacts
_410  0.4  0.5  0.6 2 A   0 0 0 1   
Short Intra H...H Contact  $A..$B. $F Ang.  

 Short intramolecular contacts may arise when H-atoms are in (false)
 calculated positions. Short intramolecular contacts may also be a sign for a   
 false structure with the molecule sitting on a site with improper site 
 symmetry (e.g. '2' instead of '-1') which may happen when a lattice
 translation is missed. Short contacts are defined using a van der Waals
 radius of 1.2 Angstrom. For intramolecular contacts alerts are generated   
 for contacts less than 2.0 Angstrom.   
#=============================================================================
# >>> Test for short non-bonding inter H..H contacts
_411    0  0.4  0.6 2 A   0 0 0 1   
Short Inter H...H Contact  $A..$B. $F Ang.  

 Short intermolecular H..H contacts may indicate incorrectly determined 
 structures (i.e. wrong symmetry, missed translation symmetry, wrong position   
 with reference to the symmetry elements, hydrogen atoms on atoms where there   
 should not be any  etc..)  
 Short intermolecular contacts may be indicative for inconsistent symmetry  
 data (e.g. coordinates for space-group P43 and symmetry specified as P41 or
 P21/n & P21/c confusions). Short contacts are defined using a van der Waals
 radius of 1.2 Angstrom. For intermolecular contacts, an alert is generated 
 for contacts less than 2.4 Angstrom.   
#=============================================================================
# >>> Test for short non-bonding intra H..H contacts (involving XH3)
_412  0.5  0.6  0.7 2 A   0 0 0 1   
Short Intra XH3 .. XHn     $A..$B. $F Ang.  

 Short intramolecular contacts may arise when H-atoms are in (false)
 calculated positions. Short intramolecular contacts may also be a sign for a   
 false structure with the molecule sitting on a site with improper site 
 symmetry (e.g. '2' instead of '-1') which may happen when a lattice
 translation is missed. Short contacts are defined using a van der Waals
 radius of 1.2 Angstrom. Short H .. H contact involving CH3 H-atoms are often   
 hampered by the fact that they involve H atoms at not optimal calculated   
 positions. 
#=============================================================================
# >>> Test for short non-bonding inter H..H contacts (involving XH3)
_413  0.0  0.4  0.5 2 A   0 0 0 1   
Short Inter XH3 .. XHn     $A..$B. $F Ang.  

 Short intermolecular H..H contacts may indicate incorrectly determined 
 structures (i.e. wrong symmetry, missed translation symmetry, wrong position   
 with reference to the symmetry elements, hydrogen atoms on atoms where there   
 should not be any  etc..). Short intermolecular contacts may be indicative 
 for inconsistent symmetry data (e.g. coordinates for space-group P43 and   
 symmetry specified as P41 or P21/n & P21/c confusions). Short contacts are 
 defined using a van der Waals radius of 1.2 Angstrom. Short H .. H contact 
 involving CH3 H-atoms are often hampered by the fact that they involve 
 H atoms at not optimal calculated positions.   
#=============================================================================
# >>> Test for short non-bonding intra D-H..H-X contacts
_414  0.4  0.5  0.6 2 A   0 0 0 1   
Short Intra D-H..H-X       $A..$B. $F Ang.  

 Short intra D-H..H-X contact. This might be a di-hydrogen bond of the type 
 B-H..H-O.  See Crabtree et al. Acc. Chem. Res. 1996, 29, 348-354.  
#=============================================================================
# >>> Test for short non-bonding inter D-H..H-X contacts
_415  0.1  0.4  0.5 2 A   0 0 0 1   
Short Inter D-H..H-X       $A..$B. $F Ang.  

 Short inter D-H..H-X contact. This might be a di-hydrogen bond of the type 
 B-H..H-O. See: Crabtree et al. Acc. Chem. Res. 1996, 29, 348-354.  
#=============================================================================
# >>> Test for short non-bonding intra D-H..H-D contacts
_416  0.4  0.5  2.5 2 A   0 0 0 1   
Short Intra D-H..H-D       $A..$B. $F Ang.  

 Short non-bonding intra D-H..H-D contacts may be related to disordered or  
 misplaced H-atoms. 
#=============================================================================
# >>> Test for short non-bonding inter D-H..H-D contacts
_417    0  0.3  0.6 2 A   0 0 0 1   
Short Inter D-H..H-D       $A..$B. $F Ang.  

 Short non-bonding inter D-H..H-D contacts may be related to disordered or  
 misplaced H-atoms. Experience has shown that any intermolecular H...H 
 separation of less than 1.8 Angstroms between unit-occupancy H atoms is a
 clear indicator that one or both of these H atoms may be wrongly placed.
#=============================================================================
# >>> Test for D-H bonds without acceptor 
_420    0  1.5   99 2 A   0 0 0 1   
D-H Bond Without Acceptor  $A--$B.     Please Check 

 Potential hydrogen bond donors are checked for the presence of suitable
 acceptors using commonly used (Jeffrey) H-bond criteria. As a general rule 
 there should be an acceptor for each donor. Exceptions are very rare for O-H   
 and more common for -NH and -NH2. A common error is an -OH with Hydrogen atom
 on a calculated position with O-H pointing in the wrong direction.  
#=============================================================================
# >>> Test for short non-bonding inter D...A contacts   
_430    0 0.19 0.50 2 A   0 0 0 1   
Short Inter D...A Contact  $A..$B. $F Ang.  

 This test alerts for possibly missed Hydrogen bonds as indicated by short  
 (i.e. shorter than sum of the van der Waals radii - 0.2 Angstrom)  
 Donor - Acceptor atom distances.

 Note: Short C=O .. O=C are observed sometimes when part of three-centre
 O-H, N-H or C-H O..O bridging. 
#=============================================================================
# >>> Test for short non-bonding inter HL...A contacts  
_431 0.10 0.30 0.50 2 A   0 0 0 1   
Short Inter HL..A Contact  $A..$B. $F Ang.  

 This test reports on short intermolecular Halogen .. Donor/Acceptor
 atom-type distances.   
#=============================================================================
# >>> Test for short non-bonding inter X...Y contacts   
_432  0.2 0.30 0.50 2 A   0 0 0 1   
Short Inter X...Y Contact  $A..$B. $F Ang.  

 This test raised an ALERT for short intermolecular contacts.   
 In general, intermolecular contact distances should be not much smaller than   
 the sum of the associated van der Waals Radii. More often than not, such   
 short contacts can be a warning sign for errors. All short contacts should 
 therefore be examined in some detail. Interesting exceptions are carbonyl- 
 carbonyl interactions that often feature short O...C contacts (see Allen   
 et al. (1998) B54, 320-329, short NO2 O...O interactions and BF4(-) to 
 (aromatic) carbon contacts.
#=============================================================================
# >>> Test for short non-bonding minor..minor inter X...Y contacts  
_433  0.5 0.85 1.00 4 A   0 0 0 1   
Short Inter X...Y Contact  $A..$B. $F Ang.  

 This test raised an ALERT for short intermolecular contacts between minor  
 disorder components. In general, intermolecular contact distances should be
 not much smaller than the sum of the associated van der Waals Radii. More  
 often than not, such short contacts can be a warning sign for errors. All  
 short contacts should therefore examined in some detail. Interesting   
 exceptions are carbonyl-carbonyl interactions that often feature short O...C   
 contacts (see Allen et al. (1998) B54, 320-329.
#=============================================================================
# >>> Test for short non-bonding inter HL...HL contacts 
_434 0.10 0.45 0.70 2 A 0 0 0 1 
Short Inter HL..HL Contact $A..$B. $F Ang.  

 This test reports on short intermolecular Halogen .. Halogen type distances.   
 Note: Bridging I- ions in a X-I...I-...I-Y chain may invoke level B ALERTs. 
#=============================================================================
# >>> Test for too large H...A  
_480 -.12 0.25  0.5 4 A   0 0 0 1   
Long H...A H-Bond Reported $A..$B. $F Ang.  

 Check this (unrealistically) long reported H..A contact.   
 Jeffrey criterium: Contact  <   vdWR(H) + vdWR(A) - 0.12 Angstrom. 
#=============================================================================
# >>> Test for too large D...A  
_481  0.5  1.0  2.0 4 A   0 0 0 1   
Long D...A H-Bond Reported $A..$B. $F Ang.  

 Check this (unrealistically) long reported D..A contact.   
 Jeffrey criterium: Contact  <   vdWR(D) + vdWR(A) + 0.50 Angstrom. 
#=============================================================================
# >>> Test for too small D-H...A angle  
_482  80. 90.0 100. 4 A   0 0 0 1   
Small D-H..A Angle Rep for $A..$B. $F Degree

 Check this unrealistically small reported D-H..A Angle.
 Jeffrey criterium: D-H..A Angle > 100 degrees. 
#=============================================================================
# >>> Test for not rounded D-H...A angle
_484    0    2    2 4 I   0 0 0 1   
Round D-H..A Angle Rep for $A..$B. $I Degree

 D-H..A angles without s.u. should be rounded to integer values for 
 publication purposes (Required for Acta Cryst.).   
#=============================================================================
# >>> Test for (unreported) solvent accessible voids
_601   30  100  200 2 A   0 0 0 1   
Unit Cell Contains Solvent Accessible VOIDS of . $I Ang**3  

 Crystal structures in general do not contain large solvent accessible voids
 in the lattice. Most structures lose their long-range ordering when solvent
 molecules leave the crystal. Only when the remaining network is strongly   
 bonded (e.g. zeolites and some hydrogen bonded networks) the crystal   
 structure may survive. Residual voids in a structure may indicate the
 omission of (disordered) density from the model. Disordered density may go
 undetected when smeared since peak search programs are not designed to locate
 maxima on density ridges. The presence or absence of residual density in the
 void may be verified on a printed/plotted difference Fourier map or with
 PLATON/SQUEEZE. Voids of 40 Ang**3 may accommodate H2O. Small molecules such
 as Tetrahydrofuran have typical volumes in the 100 to 200 Ang**3 range. This
 test reports the volume of the largest solvent accessible void in the 
 structure. A paper reporting a crystal structure with a significant solvent 
 accessible void should at the least discuss the issue.
#=============================================================================
# >>> Test for TOO LARGE (unreported) solvent accessible voids  
_602    0    0    0 2 A   0 0 0 1   
Solvent Accessible VOID(S) in Structure ........          ! Check

 This test reports on a solvent accessible void in the structure, too large 
 or too time consuming for the current PLATON version for a more detailed   
 analysis as part of the validation run. Use the SOLV option for more details.  
 Such a warning might also indicate that the symmetry is incomplete 
 e.g. should have been specified as P-1 and not P1, leaving out half of 
 the unit cell content. 
#=============================================================================
# >>> Test for TOO LARGE Unit Cell for VOID search  
_603    0    0    0 4   A 0 0 0 1   
Unit Cell TOO large for VOID SEARCH in Structure          ! Info

 No search for solvent accessible VOIDS done as part of VALIDATION in   
 view of large unit-cell.   
#=============================================================================
# >>> Test for TOO Many VOIDS   
_604    0    0    0 4 A   0 0 0 1   
Too Many VOIDS Detected in Structure .............        ! Info

 Too many solvent accessible VOIDS. 
# ============================================================================  
# >>> Test for (reported) solvent accessible voids 
_605    0    0    0 4 A   0 0 0 1   
Largest Solvent Accessible VOID in the Structure $I A**3

 Crystal structures in general do not contain large solvent accessible voids
 in the lattice. Most structures lose their long-range ordering when solvent
 molecules leave the crystal. Only when the remaining network is strongly   
 bonded (e.g. zeolites and some hydrogen bonded networks) the crystal   
 structure may survive. 
 Residual voids in a structure may indicate the omission of (disordered)
 density from the model. Disordered density may go undetected when smeared  
 since peak search programs are not designed to locate maxima on density
 ridges. The presence or absence of residual density in the void may be 
 verified on a printed/plotted difference Fourier map or with PLATON/SQUEEZE.   
 Voids of 40 Ang**3 may accommodate H2O. Small molecules such as
 Tetrahydrofuran have typical volumes in the 100 to 200 Ang**3 range.   
 This test reports the volume of the largest solvent accessible void in the 
 structure. 
 A paper reporting a crystal structure with a significant solvent accessible
 void should at the least discuss the issue.

 Note: The use of PLATON/SQUEEZE was reported in the CIF.
#=============================================================================
# >>> Test for TOO LARGE (reported) solvent accessible voids
_606    0    0    0 4 A   0 0 0 1   
Solvent Accessible VOID(S) in Structure ........          ! Info

 This test reports on a solvent accessible void in the structure, too large 
 or too time consuming for the current PLATON version for a more detailed   
 analysis as part of the validation run. Use the SOLV option for more details.  
 Such a warning might also indicate that the symmetry is incomplete 
 e.g. should have been specified as P-1 and not P1, leaving out half of 
 the unit cell content. 
#=============================================================================
# >>> Test for skipped VOID Test in case of severe disorder
_607    0    0    0 4 A   0 0 0 1   
VOID Test Skipped Due to Severe Disorder .......          ! Info

 Void test Skipped. 
#=============================================================================
# >>> Test for too many atoms for ADDSYM test as part of checkCIF   
_608    0    0    0 4 A   0 0 0 1   
ADDSYM Test Skipped (Too Time-consuming) .......          ! Info

 The ADDSYM test is skipped as part of the checkCIF run when the symmetry   
 generated cell content gets too large and the calculation too time consiming.  
 The calculation can still be done via the ADDSYM tool in PLATON.   
#=============================================================================
# >>> Check for missing SQUEEZE or MASK info
_609    0    0    0 4 A   0 0 0 1
SQUEEZE or MASK Info missing, given ABIN Record           ! Check 

 The presence of an ABIN instruction in the SHELXL .ins file implies the use 
 of the PLATON/SQUEEZE or OLEX2/MASK tool to take into account the disordered
 solvent contribution to the calculated structure factors. The corresponding
 procedure details, generated by those programs, appear to be absent from or
 incorrectly modified as part of the CIF embedded .fab file. 
#=============================================================================
# >>> Report the use of the SHELXL/SWAT instruction 
_650    0    0    0 4 A   0 0 0 1   
SWAT Instruction Used to Model Solvent Disorder           ! Report  

 This test reports the use of the SHELXL/SWAT instruction for the modelling 
 of the disordered solvent contribution to the calculated structure factors.
#=============================================================================
# >>> Test for radiation type specification 
_660    0    0    0 1 A   1 0 0 0   
No Valid _diffrn_radiation_type Value Reported .     Please Do !

 Examples of expected values are 'MoKa', 'synchrotron', 'neutron', 'electron'   
#=============================================================================
# >>> Check for BLANK records in embedded hkl file
_697    0    0    0 1 A   1 0 0 0
Number of Blank Records in CIF embedded hkl File $I Check   

 A number of blank records interspersed in the CIF embedded hkl file have been
 removed.
#=============================================================================
# >>> Check for _shelx_include_file_checksum
_698    0    0    0 1 A   1 0 0 0   
$A_shelx_include_file_checksum in CIF ...     Please Check  

 The supplied CIF contains a '_shelx_include_file' record but not a valid   
 associated '_shelx_include_file_checksum' record or valid value..  
 This include file is called from <shelx>.ins and is needed for the refinement  
 and re-creation of the associated .fcf file (used for a detailed analysis of   
 the refinement result). The calculated and reported checksums should be
 identical. Only characters with an ASCII value higher than 32 contribute to
 the checksum.  An embedded include file might be broken, either due to 
 tranfer errors or to deliberate or accidental post-refinement editing of its   
 content.   
#=============================================================================
# >>> Test for _exptl_crystal_description value 
_699    0    0    0 1 A   1 0 0 0   
Missing _exptl_crystal_description Value .......     Please Do !

 Examples of expected values are 'block', 'needle', 'plate', 'sphere',  
 'cylinder'. In case of 'cylinder' or 'sphere' also provide a value for 
 '_exptl_size_rad'. 
#=============================================================================
# >>> Test for consistency of bonds and coordinates in CIF  
_701  1.0  2.0  3.0 1 A   0 0 0 1   
Bond    Calc$X, Rep$Y, Dev.. $F Sigma   

 Bond distances given in the CIF are cross-checked with corresponding   
 values calculated from the coordinates.  Alerts are set at 1,2 and 3 sigma 
 deviation levels.  
 Note: Default s.u.'s are used where no s.u. given (e.g. for C-H)   
 In general, all differences should be within the associated s.u.   
 Small differences may arise from rounding. 
 Very large deviation (or zero distance) normally indicate incorrectly  
 specified symmetry operations on the associated atoms, or 'cut-and-pasting'
 of incompatible CIF's. 
#=============================================================================
# >>> Test for consistency of angles and coordinates in CIF 
_702  1.0  2.0  3.0 1 A   0 0 0 1   
Angle   Calc$X, Rep$Y, Dev.. $F Sigma   

 Bond Angles given in the CIF are cross-checked with corresponding values   
 calculated from the coordinates.  Alerts are set at 1,2 and 3 sigma
 deviation levels.  
 In general, all differences should be within the associated s.u.   
 Small differences may arise from rounding. Very large deviations normally  
 indicate incorrectly specified symmetry operations on the associated atoms,
 or 'cut-and-pasting' of incompatible CIF's.
#=============================================================================
# >>> Test for consistency of torsions and coordinates in CIF   
_703  1.0  2.0  3.0 1 A   0 0 0 1   
Torsion Calc$X, Rep$Y, Dev.. $F Sigma   

 Torsion angles given in the CIF are cross-checked with corresponding values
 calculated from the coordinates.  Alerts are set at 1,2 and 3 sigma
 deviation levels.  
 In general, all differences should be within the associated s.u.   
 Small differences may arise from rounding. Very large deviations normally  
 indicate incorrectly specified symmetry operations on the associated atoms,
 or 'cut-and-pasting' of incompatible CIF's.
#=============================================================================
# >>> Test for consistency of contact distances and coordinates in CIF  
_704  1.0  2.0  3.0 1 A   0 0 0 1   
Contact Calc$X, Rep$Y, Dev.. $F Sigma   

 Intermolecular contacts listed in the CIF are checked against the  
 coordinates in the CIF.
 Alerts are set at 1,2 and 3 sigma deviation levels.
#=============================================================================
# >>> Test for consistency of H-bond D-H distances and coordinates in CIF   
_705  1.0  2.0  3.0 1 A   0 0 0 1   
D-H     Calc$X, Rep$Y, Dev.. $F Sigma   

 Hydrogen-Bond D-H listed in the CIF is checked.  Alerts are set at 
 1,2 and 3 sigma deviation levels.  
#=============================================================================
# >>> Test for consistency of H-bond H..A distances and coordinates in CIF  
_706  1.0  2.0  3.0 1 A   0 0 0 1   
H...A   Calc$X, Rep$Y, Dev.. $F Sigma   

 Hydrogen-Bond H..A listed in the CIF is checked. Alerts are set at 1,2 and 
 3 sigma deviation levels.  

 This ALERT is generally related to incorrect symmetry codes. The symmetry  
 number s in the symmetry code s_pqr should correspond to the expression
 for s in the CIF. Those expressions can be different for different 
 software packages. E.g. pasting H-bond table data generated with PLATON
 into a CIF generated with SHELXL may raise this ALERT. Manual correction   
 of the symmetry code should be trivial.
#=============================================================================
# >>> Test for consistency of H-bond D..A distances and coordinates in CIF  
_707  1.0  2.0  3.0 1 A   0 0 0 1   
D...A   Calc$X, Rep$Y, Dev.. $F Sigma   

 Hydrogen-Bond D..A listed in the CIF is checked. Alerts are set at 1,2 and 
 3 sigma deviation levels.  

 This ALERT is generally related to incorrect symmetry codes. The symmetry  
 number s in the symmetry code s_pqr should correspond to the expression
 for s in the CIF. Those expressions can be different for different 
 software packages. E.g. pasting H-bond table data generated with PLATON
 into a CIF generated with SHELXL may raise this ALERT. Manual correction   
 of the symmetry code should be trivial.
#=============================================================================
# >>> Test for consistency of H-bond D-H..A angles and coordinates in CIF   
_708  1.0  2.0  3.0 1 A   0 0 0 1   
D-H..A  Calc$X, Rep$Y, Dev.. $F Sigma   

 Hydrogen-Bond Angle D-H..A listed in the CIF is checked. Alerts are set at 
 1,2 and 3 sigma deviation levels.  

 This ALERT is generally related to incorrect symmetry codes. The symmetry  
 number s in the symmetry code s_pqr should correspond to the expression
 for s in the CIF. Those expressions can be different for different 
 software packages. E.g. pasting H-bond table data generated with PLATON
 into a CIF generated with SHELXL may raise this ALERT. Manual correction   
 of the symmetry code should be trivial.
#=============================================================================
# >>> Test for meaningless 'linear' torsion angles in the CIF   
_710    0    0    0 4 I   0 0 0 1   
Delete 1-2-3 or 2-3-4 Linear Torsion Angle ... #  $A Do !   

 Torsion angles specified in the CIF are checked for the
 'linear variety' where one or both of the 1-2-3 and 2-3-4 bond 
 angles are close to 180 Deg. SHELXL97 will generate those 'torsions' for   
 molecules containing linear moieties (E.g. Metal-C=O). 
#=============================================================================
# >>> Test for label problems for bonds in the CIF  
_711    0   99   99 1 A   0 0 0 1   
BOND    Unknown or Inconsistent Label ..........  $A Check  

 When labels are found on geometry items (bonds, angles etc.) that are not in   
 the coordinate list, and alert _71n is issued, related to alert _70n.  
#=============================================================================
# >>> Test for label problem for angles in CIF  
_712    0   99   99 1 A   0 0 0 1   
ANGLE   Unknown or Inconsistent Label ..........  $A Check  

 When labels are found on geometry items (bonds, angles etc.) that are not in   
 the coordinate list, and alert _71n is issued, related to alert _70n.  
#=============================================================================
# >>> Test for label problem for torsions in the CIF
_713    0   99   99 1 A   0 0 0 1   
TORSION Unknown or Inconsistent Label ..........  $A Check  

 When labels are found on geometry items (bonds, angles etc.) that are not in   
 the coordinate list, and alert _71n is issued, related to alert _70n.  
#=============================================================================
# >>> Test for label problem for contact distances in the CIF   
_714    0   99   99 1 A   0 0 0 1   
CONTACT Unknown or Inconsistent Label ..........  $A Check  

 When labels are found on geometry items (bonds, angles etc.) that are not in   
 the coordinate list, and alert _71n is issued, related to alert _70n.  
#=============================================================================
# >>> Test for label problem for H-bond D-H distances in the CIF
_715    0   99   99 1 A   0 0 0 1   
D-H     Unknown or Inconsistent Label ..........  $A Check  

 When labels are found on geometry items (bonds, angles etc.) that are not in   
 the coordinate list, and alert _71n is issued, related to alert _70n.  
#=============================================================================
# >>> Test for label problem for H-bond H..A distances in the CIF   
_716    0   99   99 1 A   0 0 0 1   
H...A   Unknown or Inconsistent Label ..........  $A Check  

 When labels are found on geometry items (bonds, angles etc.) that are not in   
 the coordinate list, and alert _71n is issued, related to alert _70n.  
#=============================================================================
# >>> Test for label problem for  H-bond D..A distances in the CIF  
_717    0   99   99 1 A   0 0 0 1   
D...A   Unknown or Inconsistent Label ..........  $A Check  

 When labels are found on geometry items (bonds, angles etc.) that are not in   
 the coordinate list, and alert _71n is issued, related to alert _70n.  
#=============================================================================
# >>> Test for label problem for H-bond D-H..A angles in the CIF
_718    0   99   99 1 A   0 0 0 1   
D-H..A  Unknown or Inconsistent Label ..........  $A Check  

 When labels are found on geometry items (bonds, angles etc.) that are not in   
 the coordinate list, and alert _71n is issued, related to alert _70n.  
#=============================================================================
# >>> Test for unusual and nonstandard labels   
_720    0    2    2 4 I   0 0 0 1   
Number of Unusual/Non-Standard Labels .......... $I Note

 Up to 4 Character Labels of the type C11, H101, N10A, i.e. chemical symbol +   
 number + optional letter are to be preferred.  
 Note: SHELXL based refinements may use labels up to 7 characters (Including
 residue and or disorder information).
#=============================================================================
# >>> Test for consistency of bonds and coordinates in the CIF  
_721  1.0  2.0  3.0 1 A   0 0 0 1   
Bond    Calc$X, Rep$Y Dev... $F Ang.

 Same as 701 but for distance without s.u. (esd). Difference is tested in terms 
 of Angstroms.  
#=============================================================================
# >>> Test for consistency of angles and coordinates in the CIF 
_722  1.0  2.0  3.0 1 A   0 0 0 1   
Angle   Calc$X, Rep$Y Dev... $F Degree  

 Same as 702 but for angle without s.u. (esd). Difference is tested in terms of 
 Degrees.   
#=============================================================================
# >>> Test for consistency of torsions and coordinates in the CIF   
_723  1.0 999. 999. 1 A   0 0 0 1   
Torsion Calc$X, Rep$Y Dev... $F Sigma   

 Same as 703 but for torsion without s.u. (esd). Difference is tested in terms  
 of Degrees.
#=============================================================================
# >>> Test for consistency of contact distances and coordinates in the CIF  
_724  1.0  2.0  3.0 2 A   0 0 0 1   
Contact Calc$X, Rep$Y Dev... $F Ang.

 Same as 704, but for distance without s.u. (esd). Difference is tested in  
 terms of Angstroms.
#=============================================================================
# >>> Test for consistency of H-bond D-H distances and Coordinates in the CIF   
_725  1.0  2.0  3.0 2 A   0 0 0 1   
D-H     Calc$X, Rep$Y Dev... $F Ang.

 Same as 705 but for distance without s.u. (esd). Differences are tested in 
 terms of Angstrom. 
#=============================================================================
# >>> Test for consistency of H-bond H..A distances and coordinates in the CIF  
_726  1.0  2.0  3.0 2 A   0 0 0 1   
H...A   Calc$X, Rep$Y Dev... $F Ang.

 Same as 706 but for distance without s.u. (esd). Differences are tested in 
 terms of Angstrom. 
#=============================================================================
# >>> Test for consistency of H-bond D..A distances and coordinates in the CIF  
_727  1.0  2.0  3.0 1 A   0 0 0 1   
D...A   Calc$X, Rep$Y Dev... $F Ang.

 Same as 707 but for distance without s.u. (esd). Differences are tested in 
 terms of Angstrom. 
#=============================================================================
# >>> Test for consistency of H-bond D-H..A angles and coordinates in the CIF   
_728  1.0  2.0  3.0 1 A   0 0 0 1   
D-H..A  Calc$X, Rep$Y Dev... $F Degree  

 Same as ALERT 708 but for angle without s.u. (esd). Differences are tested 
 in terms of Degrees.   
#=============================================================================
# >>> Test for consistency of bond s.u.'s and coordinate s.u.'s in the CIF  
_731  3.0  6.0 12.0 1 A   0 0 0 1   
Bond    Calc$X, Rep$Y ...... $I su-Rat  

 A large ratio of the reported and calculated bond s.u.'s is found. 
 The use of a DFIX instruction might cause such a warning since 
 calculated s.u.'s are based on reported variances only.
 Note_1: s.u.'s on the unit-cell dimensions are taken into account in the   
 calculation of expected s.u.'s. This may result in large differences   
 between expected and reported s.u.'s when this contribution is not included
 in the reported s.u.'s, in particular for inaccurate unit-cells.   
 Note_2: Another source for the discrepancy between calculated and  
 reported s.u.'s can be that the validation software has access only to 
 the variances of the refined parameters as opposed to the full co-variance 
 matrix used by e.g. SHELXL for the calculation of derived parameters   
 with associated s.u.'s. Constrained/restrained refinement may cause large  
 co-variances.  
#=============================================================================
# >>> Test for consistency of angles and coordinates in CIF s.u.'s  
_732  2.0  4.0  8.0 1 A   0 0 0 1   
Angle   Calc$X, Rep$Y ...... $F s.u.-Rat

 A large ratio of the reported and calculated bond angle s.u.'s is found.   
 This check should warn for erroneous rounding: E.g. 105.5(19) to 105.5(2) or   
 105.0(5) to 105(5) etc. Note: Large differences are possible when certain  
 constraints/restraints were applied in the refinement (e.g. the FLAT option
 in SHELXL97).  
 Note_1: s.u.'s on the unit-cell dimensions are taken into account in the   
 calculation of expected s.u.'s. This may result in large differences   
 between expected and reported s.u.'s when this contribution is not included
 in the reported s.u.'s, in particular for inaccurate unit-cells.   
 Note_2: Another source for the discrepancy between calculated and  
 reported s.u.'s can be that the validation software has access only to 
 the variances of the refined parameters as opposed to the full co-variance 
 matrix used by e.g. SHELXL for the calculation of derived parameters   
 with associated s.u.'s. Constrained/restrained refinement may cause large  
 co-variances.  
#=============================================================================
# >>> Test for consistency of torsions and coordinates in CIF s.u's
_733  4.0  6.0  8.0 1 A   0 0 0 1   
Torsion Calc$X, Rep$Y ...... $F s.u.-Rat

 A large ratio of the reported and calculated torsion angle s.u.'s is found.
 This check should warn for erroneous rounding: E.g. 105.5(19) to 105.5(2)  
 or 105.0(5) to 105(5) etc. 
 Note_1: s.u.'s on the unit-cell dimensions are taken into account in the   
 calculation of expected s.u.'s. This may result in large differences   
 between expected and reported s.u.'s when this contribution is not included
 in the reported s.u.'s, in particular for inaccurate unit-cells.   
 Note_2: Another source for the discrepancy between calculated and  
 reported s.u.'s can be that the validation software has access only to 
 the variances of the refined parameters as opposed to the full co-variance 
 matrix used by e.g. SHELXL for the calculation of derived parameters   
 with associated s.u.'s. Constrained/restrained refinement may cause large  
 co-variances.  
#=============================================================================
# >>> Test for consistency of contact distance s.u. and coordinate s.u. in CIF  
_734  2.0  4.0  8.0 1 A   0 0 0 1   
Contact Calc$X, Rep$Y ...... $F s.u.-Rat

 A large ratio of the reported and calculated contact distance s.u.'s is found. 
 Note: s.u.'s on the unit-cell dimensions are taken into account in the 
 calculation of expected s.u.'s. This may result in large differences   
 between expected and reported s.u.'s when this contribution is not included
 in the reported s.u.'s, in particular for inaccurate unit-cells.   
#=============================================================================
# >>> Test for consistency of H-bond D-H dist. s.u. and coordinate s.u. in CIF
_735  2.0  4.0  8.0 1 A   0 0 0 1   
D-H     Calc$X, Rep$Y ...... $I s.u.-Rat

 A large ratio of the reported and calculated H-bond D-H distance s.u.'s is 
 found. The use of a DFIX instruction might cause such a warning since  
 calculated s.u.'s are based on reported variances only.
 Note: s.u.'s on the unit-cell dimensions are taken into account in the 
 calculation of expected s.u.'s. This may result in large differences   
 between expected and reported s.u.'s when this contribution is not included
 in the reported s.u.'s, in particular for inaccurate unit-cells.   
#=============================================================================
# >>> Test for consistency of H-bond H..A distance s.u. and coordinates in CIF  
_736  2.0  4.0  8.0 1 A   0 0 0 1   
H...A   Calc$X, Rep$Y ...... $F s.u.-Rat

 A large ratio of the reported and calculated H-bond H..A distance s.u.'s   
 is found.  
 Note: s.u.'s on the unit-cell dimensions are taken into account in the 
 calculation of expected s.u.'s. This may result in large differences   
 between expected and reported s.u.'s when this contribution is not included
 in the reported s.u.'s, in particular for inaccurate unit-cells.   
#=============================================================================
# >>> Test for consistency of H-bond D..A distance s.u. and coordinates in CIF  
_737  2.0  4.0  8.0 1 A   0 0 0 1   
D...A   Calc$X, Rep$Y ...... $F s.u.-Rat

 A large ratio of the reported and calculated H-Bond D...A distance s.u.'s is   
 found. 
#=============================================================================
# >>> Test for consistency of H-bond D-H..A angle and coordinates in CIF s.u.   
_738  2.0  4.0  8.0 1 A   0 0 0 1   
D-H..A  Calc$X, Rep$Y ...... $F s.u.-Rat

 A large ratio of the reported and calculated H-Bond D-H..A angle s.u.'s
 is found.  
 Note: s.u.'s on the unit-cell dimensions are taken into account in the 
 calculation of expected s.u.'s. This may result in large differences   
 between expected and reported s.u.'s when this contribution is not included
 in the reported s.u.'s, in particular for inaccurate unit-cells.   
#=============================================================================
# >>> Test for missing bond s.u. in the CIF 
_741  0.0 99.0 99.0 1 A   0 0 0 1   
Bond    Calc$X, Rep$Y ......    Missing s.u.

 Likely Missing s.u. on Bond in CIF.
#=============================================================================
# >>> Test for missing angle s.u. in the CIF
_742  0.0 99.0 99.0 1 A   0 0 0 1   
Angle   Calc$X, Rep$Y ......    Missing s.u.

 Likely Missing s.u. on Bond angle in CIF.  
#=============================================================================
# >>> Test for missing torsion s.u. in the CIF  
_743  0.0 99.0 99.0 1 A   0 0 0 1   
Torsion Calc$X, Rep$Y ......    Missing s.u.

 Likely Missing s.u. on Torsion angle in CIF.   
#=============================================================================
# >>> Test for missing contact distance s.u. in the CIF
_744  0.0 99.0 99.0 1 A   0 0 0 1   
Contact Calc$X, Rep$Y ......    Missing s.u.

 Likely missing s.u. on contact Distance in CIF.
#=============================================================================
# >>> Test for missing H-bond D-H distance s.u. in the CIF  
_745  0.0 99.0 99.0 1 A   0 0 0 1   
D-H     Calc$X, Rep$Y ......    Missing s.u.

 Likely missing s.u. on H-Bond D-H distance in CIF. 
#=============================================================================
# >>> Test for missing H-bond H..A distance s.u. in the CIF 
_746  0.0 99.0 99.0 1 A   0 0 0 1   
H...A   Calc$X, Rep$Y ......    Missing s.u.

 Likely missing s.u. on H-Bond H...A distance in CIF.   
#=============================================================================
# >>> Test for missing H-bond D..A distance s.u. in the CIF 
_747  0.0 99.0 99.0 1 A   0 0 0 1   
D...A   Calc$X, Rep$Y ......    Missing s.u.

 Likely missing s.u. on H-Bond D...A distance in CIF.   
#=============================================================================
# >>> Test for missing H-bond D-H..A angle s.u. in the CIF  
_748  0.0 99.0 99.0 1 A   0 0 0 1   
D-H..A  Calc$X, Rep$Y ......    Missing s.u.

 Likely missing s.u. on H-Bond D-H..A angle in CIF. 
#=============================================================================
# >>> Test for senseless bond s.u. in the CIF   
_751  0.0 99.0 99.0 4 A   0 0 0 1   
Bond    Calc$X, Rep$Y ......  Senseless s.u.

 An s.u. should not be given in the CIF for constrained distances.  
 Please check for proper refinement status flags (e.g. R)   
#=============================================================================
# >>> Test for senseless angle s.u. in the CIF  
_752  0.0 99.0 99.0 4 A   0 0 0 1   
Angle   Calc$X, Rep$Y ......  Senseless s.u.

 An s.u. should not be given in the CIF for constrained angles. 
 Please check for proper refinement status flags (e.g. R)   
#=============================================================================
# >>> Test for senseless torsion s.u. in the CIF
_753  0.0 99.0 99.0 4 A   0 0 0 1   
Torsion Calc$X, Rep$Y ......  Senseless s.u.

 An s.u. should not be given in the CIF for constrained torsion angles. 
 Please check for proper refinement status flags (e.g. R)   
#=============================================================================
# >>> Test for senseless contact distance s.u. in the CIF  
_754  0.0 99.0 99.0 4 A   0 0 0 1   
Contact Calc$X, Rep$Y ......  Senseless s.u.

 An s.u. should not be given in the CIF for constrained contact distances.  
 Please check for proper refinement status flags (e.g. R)   
#=============================================================================
# >>> Test for senseless H-bond D-H distance s.u. in the CIF   
_755  0.0 99.0 99.0 4 A   0 0 0 1   
D-H     Calc$X, Rep$Y ......  Senseless s.u.

 An s.u. should not be given in the CIF for constrained distances.  
 Please check for proper refinement status flags (e.g. R).  
#=============================================================================
# >>> Test for senseless H-bond H..A distance s.u. in the CIF  
_756  0.0 99.0 99.0 4 A   0 0 0 1   
H...A   Calc$X, Rep$Y ......  Senseless s.u.

 An s.u. should not be given in the CIF for constrained distances.  
 Please check for proper refinement status flags (e.g. R).  
#=============================================================================
# >>> Test for senseless H-bond D..A distance s.u. in the CIF  
_757  0.0 99.0 99.0 4 A   0 0 0 1   
D...A   Calc$X, Rep$Y ......  Senseless s.u.

 An s.u. should not be given in the CIF for constrained distances.  
 Please check for proper refinement status flags (e.g. R).  
#=============================================================================
# >>> Test for senseless H-bond D-H..A angle s.u. in the CIF   
_758  0.0 99.0 99.0 4 A   0 0 0 1   
D-H..A  Calc$X, Rep$Y ......  Senseless s.u.

 An s.u. should not be given in the CIF for constrained angles. 
 Please check for proper refinement status flags (e.g. R)   
#=============================================================================
# >>> Test for the presence of at least one torsion angle in the CIF
_760    0    2    2 1 I   0 0 0 1   
CIF Contains no Torsion Angles .................          ? Info

 The CIF contains no torsion angle entries. This might be accomplished with 
 the SHELXL instruction CONF.   
 Inclusion is encouraged by Acta Cryst. but not necessarily so by other 
 journals.  
#=============================================================================
# >>> Test for the presence of at least one X-H in the CIF  
_761    0    2    2 1 I   0 0 0 1   
CIF Contains no X-H Bonds ......................     Please Check   

 The CIF contains no X-H Bonds. This might be caused by not using the SHELXL  
 instruction BOND $H. Inclusion is required by Acta Cryst. but not necessarily
 so by other journals.  
#=============================================================================
# >>> Test for at least one X-Y-H or H-Y-H entry in the CIF 
_762    0    2    2 1 I   0 0 0 1   
CIF Contains no X-Y-H or H-Y-H Angles ..........     Please Check   

 The CIF contains no X-Y-H or H-Y-H bond angles. This might be caused by not
 using the SHELXL instruction BOND $H. Those data should also be supplied   
 when H-atoms are introduced on calculated positions and/or refined riding  
 on their carrier atom. Inclusion is required by Acta Cryst. but not
 necessarily so by other journals. 
#=============================================================================
# >>> Test for missing bonds in the CIF 
_763 0.01  0.1  5.0 1 I   0 0 0 1   
Incomplete CIF Bond list Detected (Rep/Expd) ... $F Ratio   

 Bond list in CIF likely incomplete.
#=============================================================================
# >>> Test for overcomplete bonds in the CIF
_764  0.0  5.0  5.0 4 I   0 0 0 1   
Overcomplete CIF Bond List Detected (Rep/Expd) . $F Ratio   

 The CIF contains more bonds than the unique set, indicating redundancy.
 An example is redundancy due to the inclusion of symmetry related bonds.   
#=============================================================================
# >>> Test for erroneous 'LIST 8' instruction in the embedded .res file

_766  0.0  2.0  2.0 4 I   0 0 0 1
INS Embedded LIST 8 Instruction Should be LIST 4     Please Check
 
 The final <name>.fcf associated with the <name>.cif should have been created
 with the LIST 4 instruction (or just left out because already implicit with
 the ACTA instruction). The LIST 8 instruction will create an FCF file where 
 the observed data are detwinned making the generated <name>.fcf unsuitable 
 for checking for missed (additional) twinning and validation.
#=============================================================================
# >>> Test for erroneous 'LIST 6' instruction in the embedded .res file
_767  0.0  2.0  2.0 4 I   0 0 0 1
INS Embedded LIST 6 Instruction Should be LIST 4     Please Check
 
 The .fcf associated with the .cif should have been created with the 'LIST 4'
 instruction (or left out because already implicit with the ACTA instruction).
 LIST 6 will create an FCF file where the observed data are corrected for 
 anomalous/resonant scattering, making the generated .fcf unsuitable for
 post refinement absolute structure analysis and validation.  
#=============================================================================
# >>> TEST for CIF/RES embedded explicit scattering factor values
_768  0.0  0.0  0.0 4 I   0 0 0 1
Embedded RES Explicitly Supplied Scattering Data     Please Note 

 The supplied CIF includes explicit atomic scattering factor date in the 
 embedded .res file. Those values may or may not be identical to the standard
 values as included in current versions of SHELXL. It should be noted that
 those values will not be present as CIF data items in CIF's created with
 SHELXL. PLATON/checkCIF will use its own build-in scattering factors, that
 are identical to those used by default by SHELXL for common wavelengths,
 for its validation calculations. 
#=============================================================================
# >>> TEST for CIF embedded explicit scattering factor values
_769  0.0  0.0  0.0 4 I   0 0 0 1
CIF Embedded Explicitly Supplied Scattering Data     Please Note 

 The supplied CIF contains explicit scattering factor data as values of their
 corresponding CIF datanames. Those scattering factor data are used by 
 PLATON/checkCIF for its validation calculations as opposed to using the
 neutral scattering factor data that are stored in PLATON (which are identical 
 to those in stored in SHELXL). Those CIF reported values should be identical
 to those provided in the embedded *.ins file. 
 Current SHELXL versions do not copy scattering factor data that are explicitly
 included in the *.ins instruction file into corresponding CIF data items. 
 A reason for the use of non-standard scattering factors can be the modelling
 of charged atoms in the refinement.
#=============================================================================
# >>> Test for suspect C-H bonds in CIF (not caught otherwise)  
_770  0.0  0.0  0.0 2 A   0 0 0 1   
Suspect C-H Bond in CIF:  $A--$B . $F Ang.  

 Report on unusual C-H bonds not caught in other tests. 
#=============================================================================
# >>> Test for suspect N-H bonds in CIF (not caught otherwise)  
_771  0.0  1.4  1.5 2 A   0 0 0 1   
Check   N-H Bond in CIF: $A--$B .. $F Ang.  

 Report on unusual N-H bonds not caught in other tests. 
#=============================================================================
# >>> Test for suspect O-H bonds in CIF (not caught otherwise)  
_772  0.0  1.4  1.5 2 A   0 0 0 1   
Suspect O-H Bond in CIF: $A--$B .. $F Ang.  

 Report on unusual O-H bonds not caught in other tests. 

 Note: Exceptions can be H-atoms in acid O..H..O bridges or in H5O2+
       (Hydronium) species. 
#=============================================================================
# >>> Test for suspect C-C bonds in CIF (not caught otherwise)  
_773  0.0  0.0  0.0 2 A   0 0 0 1   
Check long C-C Bond in CIF: $A--$B $F Ang.  

 Report on unusual C-C bonds, possibly  not caught in other tests.  
 Exceptions include C-C distances of around 1.75 Ang. in e.g.   
 1,2-dicarba-closo-dodecaborane.
#=============================================================================
# >>> Test for too large/erroneous bond distance  
_774  3.5  4.0 99.0 1 A   0 0 0 1   
Check   X-Y Bond in CIF: $A--$B .. $F Ang.  

 Likely Erroneous Bond Entry.   
#=============================================================================
# >>> Test for too large/erroneous contact distance   
_775  4.0  6.0 99.0 1 A   0 0 0 1   
Check   X-Y Contact in CIF: $A--$B $F Ang.  

 Likely Erroneous Contact Entry.
#=============================================================================
# >>> Test for too large/erroneous H-bond D-H  distance   
_776  1.3  1.5  2.0 1 A   0 0 0 1   
Check   D-H Dist in CIF: $A--$B .. $F Ang.  

 Likely Erroneous D-H Entry.
#=============================================================================
# >>> Check for N..H..X+ bonds in the CIF   
_777  0.0  0.0  0.0 2 A   0 0 0 1   
Check N..H..X Bond in CIF: $A--$B  $F Ang.  

 Report N-H distance in special N..H..X+ bonds. The N .. X distance is  
 expected to be shorter than in a standard hydrogen bond.   
#=============================================================================
# >>> Check for O..H..X+ bonds in the CIF   
_778  0.0  0.0  0.0 2 A   0 0 0 1   
Check O..H..X Bond in CIF: $A--$B  $F Ang.  

 Report O-H distance in special O..H..X+ bonds. The O .. X distance is  
 expected to be shorter than in a standard hydrogen bond.   
#=============================================================================
# >>> Test for suspect angle in CIF (not caught otherwise)  
_779  0.0  0.0  0.0 4 I   0 0 0 1   
Suspect or Irrelevant (Bond) Angle(s) in CIF ...  $A Deg.   

 Possibly erroneous (Bond)angle less than 45 degree. The angle might be 
 considered for elimination from the CIF when irrelevant. This ALERT can
 also be triggered when the assigned occupancy factors are incorrect.   
#=============================================================================
# >>> Test whether the coordinates form a connected set 
_780    0    0  1.0 1 A   0 1 0 0   
Coordinates do not Form a Properly Connected Set     Please Do !

 Atoms given in a CIF should form a 'connected set', i.e. no symmetry   
 operations are needed to get atoms in a bonding position. A connected set of   
 atoms is not needed for the least squares refinement (unless hydrogen atoms
 are to be added at calculated positions). Geometry listings (bonds, angles,
 torsions & H-bonds) become unwieldy for non-connected atom sets.   
#=============================================================================
# >>> Test for Flack x value for centrosymmetric space-group
_781    0    0    0 1 A   0 0 0 1   
Flack Parameter is Given for Centro Space-Group.          ? Error   

 A Flack parameter value is erroneously given for a structure reported  
 in a centrosymmetric space-group.  
#=============================================================================
# >>> Test for unusual C-NO2 an C-CO2 moiety bond geometry  
_782    0  1.0  2.0 2 A   0 0 1 0   
Unusual Bond Geometry for $A Moiety Around    $B Check  

 Warning for a possible misassignment of C-NO2 and C-CO2 moieties.  
 The geometry of the reported moiety appears to be unusual/inconsistent.
 The C-O bond distances in C-CO2 are expected to add up to about 2.5
 Test Criteria: ALERT for C-O bond sum < 2.48 and C-C < 1.48 Angstrom   
 The N-O bond distances in C-NO2 are expected to add up to about 2.4
 Test Criteria: ALERT for N-O bond sum > 2.48 and C-C > 1.48 Angstrom   
#=============================================================================
# >>> Test for El1 in SumFormula
_787    0 99.0 99.0 4 A   0 0 0 1   
Change $A into $B in SumFormula ..     Please Do

 The numerical part for an element in the SumFormula should be dropped when '1'.
#=============================================================================
# >>> Test for El1 in MoietyFormula instead of El 
_788    0 99.0 99.0 4 A   0 0 0 1   
Change $A into $B in MoietyFormula     Please Do

 The numerical part for an element in the MoietyFormula should be dropped   
 when '1'.  
#=============================================================================
# >>> Report the number of atoms with negative _atom_site_disorder_group #  
_789    0    0    0 4 I   0 0 0 1   
Atoms with Negative _atom_site_disorder_group  # $I Check   

 A negative value of the _atom_site_disorder_group number of an atom indicates  
 whether that atom is part of a group disordered over a symmetry element.   
 Check whether this negative sign assignment applies.   
#=============================================================================
# >>> Test whether centre-of-gravity of a residue is within the unitcell box 
_790    0    2    2 4 I   0 0 0 1   
Centre of Gravity not Within Unit Cell: Resd.  # $I Note

 Unless for a good reason, molecular species should be transformed  
 (by symmetry and/or translation) so that their centres of gravity  
 are close to or within the unit-cell bounds. This is a strict rule for the 
 main species. Deviations from this general rule are for smaller additional 
 species when relevant for intermolecular interactions with the main species.   
#=============================================================================
# >>> Check the absolute configuration of chiral atom in Sohncke space-group 
_791    0    0    0 4 I   0 0 0 1   
Model has Chirality at $A  (Sohncke SpGr)  $B Verify

 A tentative (R/S) assignment is done on the basis of the geometrical and   
 atom type data in the CIF. A correct assignment depends on the algorithm   
 used to automatically detect double and triple bonds. For that reason it is
 important that the molecule is complete (i.e. all hydrogen atoms should be 
 included). In case of a chiral molecule in a centro-symmetric spacegroup, it
 is essential that the coordinate set used and the associated molecular
 (ORTEP) illustration are consistent. This can be verified by checking the  
 identical signs of relevant torsion angles. The absolute structure assignment
 should also be consistent with the lowest value of the Flack parameter and/or
 known absolute configuration.   
#=============================================================================
# >>> Check the abs. config. of chiral atom in a polar Non-Sohncke space-group 
_792    0    0    0 1 I   0 0 0 1   
Model has Chirality at $A   (Polar  SpGr)  $B Verify

 This test addresses the consistency of the absolute structure assignment   
 (i.e. polarity etc.) in non-centrosymmetric structures in space groups 
 that include improper symmetry operations (e.g. mirror planes).
 Check the (R/S) absolute configuration assignment of this atom and 
 the consistency of the absolute configuration implicit in the CIF-data 
 with that in the 'ORTEP' illustration. 
#=============================================================================
# >>> Check the abs. config. of chiral atom in a centrosymmetric space-group 
_793    0    0    0 4 A   0 0 0 1   
Model has Chirality at $A   (Centro SpGr)  $B Verify

 This test addresses the consistency of the absolute configuration assignment   
 of molecules in the reported asymmetric unit among coordinates,
 molecular presentations and chemical diagrams. 
 Check the (R/S) absolute configuration assignment of this atom and 
 the consistency of the absolute configuration implicit in the CIF-data 
 with that in the 'ORTEP' illustration. 
#=============================================================================
# >>> Report the calculated 'Valence Bond' valency for metals   
_794    0    0    0 5 A   0 0 0 1   
Tentative Bond Valency for $A $B . $F Info  

 This test reports the valency of an atom as predicted by the Valence   
 Bond Model. See:   
 N.E. Brese & M. O'Keeffe (1991) Acta Cryst. B47, 192-197.  
 I.D. Brown (2002). The Chemical Bond in Inorganic Chemistry:   
      The Bond Valence Model. Oxford University Press.  

 More explicit info on the calculations can be obtained by running the  
 calculations explicitly with the PLATON option BondValence.

 Note: The underlying theory is empirical and might not apply to the
       case at hand (e.g. charged species). 
#=============================================================================
# >>> Test for C-atom labels ordered
_795  0.0  0.0  0.0 4 I   0 0 0 1   
C-Atom in CIF Coordinate List Out-of-Sequence ..  $A Note   

 Atoms in the CIF are not given in logical order (i.e. C1, C2 etc.) 
 The recommended procedure is to sort the atom list in some logical 
 order before the final refinement cycles.  
#=============================================================================
# >>> Test for O-atom labels ordered
_796  0.0  2.0  2.0 4 I   0 0 0 1   
O-Atom in CIF Coordinate List Out-of-Sequence ..  $A Note   

 Atoms in the CIF are not given in logical order (i.e. O1, O2 etc.) 
 The recommended procedure is to sort the atom list in some logical 
 order before the final refinement cycles.  
#=============================================================================
# >>> Test for N-atom labels ordered
_797  0.0  2.0  2.0 4 I   0 0 0 1   
N-Atom in CIF Coordinate List Out-of-Sequence ..  $A Note   

 Atoms in the CIF are not given in logical order (i.e. N1, N2 etc.) 
 The recommended procedure is to sort the atom list in some logical 
 order before the final refinement cycles.  
#=============================================================================
# >>> Test for alphanumeric atom label in coordinate record  
_798  0.0  2.0  2.0 4 A   0 0 0 1   
Numeric Atom Label on Coordinate Par. Record ...  $A Check  

 Atom labels are generally not a number (i.e. starting with one or two  
 characters indicating the atom type). Labels can be erroneously numeric
 due to typing errors (e.g. 'Oxygen' typed as 'zero').  
#=============================================================================
# >>> Test for alphanumeric label in displacement pararameter record   
_799  0.0  2.0  2.0 4 A   0 0 0 1   
Numeric Label on Displacement Par. Record ......  $A Check  

 Atom labels are generally not a number (i.e. starting with one or two  
 characters indicating the atom type). Labels can be erroneously numeric
 due to typing errors (e.g. 'Oxygen' typed as 'zero').  
#=============================================================================
# >>> Test for out-of-order symmetry data   
_800  0.0  0.0  0.0 4 A   1 0 0 0   
Symmetry Specification Should Precede Cell Data.     Please Do! 

 Symmetry data (i.e. space group, symmetry operations etc.) are expected
 to be given in the CIF prior to the cell dimensions and coordinate data.
#=============================================================================
# >>> Test for missing, incomplete or out-of-order Cell data
_801  0.0  0.0  0.0 4 A   1 0 0 0   
Cell Data Missing, Incomplete or Out-of-Order ..     Please Check   

 PLATON/CheckCIF has a problem with the Cell data. A possible reason can be 
 that the cell data are missing, incomplete or out-of-sequence. 
 PLATON/CheckCIF wishes to encounter the cell and symmetry data before any  
 coordinates are given. PLATON expects the values of all six cell parameters.   
#=============================================================================
# >>> Test for input lines longer than 80 characters
_802    0   10   10 4 I   0 0 0 1   
CIF Input Record(s) with more than 80 Characters $I Info

 The CIF contains records longer than 80 characters. Not all software will  
 read beyond column 80. The CIF-1.1 definition specifies a maximum of 2048
 character per record.   
#=============================================================================
# >>> Test for loop problem in CIF-read 
_803  0.0  0.0  0.0 1 A   0 0 0 1   
Loop Problem in CIF-Reading (Too Many loop Items)    Please Check   

 Fatal Problem: Check loop data names and data for errors. There are likely
 too many or to few data in the loop.
#=============================================================================
# >>> Report on ARU-Pack problem(s) in PLATON
_804    0    1    1 5 I   0 0 0 1   
Number of ARU-Code Packing Problem(s) in PLATON  $I Info

 Problem: ARU representations turn out to be needed outside the ORTEP   
 style -5:5 unit-cell translation range. The Analysis might be incomplete.  
 The problem often occurs for structures with aliphatic chains stretching   
 over many unitcells or network structures. Transformation of the unitcell  
 content to a symmetry related position might solve the problem.
#=============================================================================
# >>> Test for insufficient coordinate data in CIF loop   
_805    0    0    0 1 A   0 0 0 1   
Fatal Problem: Insufficient Data in Atom Loop ..     Please Check   

 Check Coordinate Data Loop.
#=============================================================================
# >>> Test for insufficient U(i,j) data in CIF loop 
_806    0    2    2 4 A   1 0 0 1   
Fatal Problem: Insufficient Data in UIJ Loop ...     Please Check   

 Check UIJ Data Loop.   
#=============================================================================
# >>> Test for maximum number of atoms exceeded problem 
_807    0    0  100 5 A   0 0 0 1   
Fatal Problem: Maximum Number of Atoms Exceeded.          ! Info

 PLATON can handle up to 'NP1' in the (expanded) ATOM list. This might happen
 with disordered or network structures in high symmetry space groups. Deletion
 of the symmetry information might solve part of the problem and provide a
 partial validation. Alternatively, clicking on 'NOSYMM' on the PLATON menu
 before invoking validation might address the problem.  
#=============================================================================
# >>> Test for parseable SHELXL style weighting scheme  
_808    0    0    0 5 A   0 0 0 1   
No Parseable SHELXL Style Weighting Scheme Found     Please Check   

 The validation software did not succeed in finding/analyzing a parsable
 weighting scheme.  SHELXL style weight parameters are expected to be given in
 the format: 

 _refine_ls_weighting_details   
 'calc w=1/[\s^2^(Fo^2^)+(0.1000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'

 JANA style weight is expected to be given in the format:   

 _refine_ls_weighting_details 'w=1/(\s^2^(I)+0.0016I^2^)'   


  Do not edit this string or make it into a text block between ';'. 
#=============================================================================
# >>> Report on parsing problem of SHELXL style weighting scheme 
_809    0    0    0 1 A   0 0 0 1   
Can not Parse the SHELXL Weighting Scheme String     Please Check   

 The software did not succeed in Parsing the SHELXL style weighting scheme.
 The string might have been edited or of the more than 2 parameter variety
 (see SHELXL manual).   
#=============================================================================
# >>> Report Out-of-Memory problem in PLATON
_810    0    0    0 5 A   0 0 0 1   
Out-of-Memory Problem in PLATON/ASYM ...........          ! Info

 Analysis for missing reflections may be incomplete due to an out-of-memory 
 problem.   
#=============================================================================
# >>> Report on no ADDSYM analysis executed for too many disordered atoms case 
_811    0    2    2 5 A   0 0 0 1   
No ADDSYM Analysis: Too Many Excluded Atoms ....          ! Info

 The ADDSYM test for missed symmetry is not executed for structures with too
 many disordered atoms. 
#=============================================================================
# >>> Report for aliases overflow problem in PLATON   
_812    0    0    2 5 A   0 0 0 1   
PLATON problem - Too Many Aliased Atoms. Max =   $I 

 Non-standard labels are aliased into acceptable labels. The maximum number 
 of aliases is reached. 
#=============================================================================
# >>> Test for insufficient data on HKLF record in the CIF  
_813    0    0    0 1 A   0 0 0 1   
No Numerical Data in HKLF (.res) Record in CIF .     Please Check   

 Check the HKLF record in the SHELXL style .res is embedded in the CIF. 
 This record should show either 'HKLF 4' or 'HKLF 5'. The information in this
 record is used to establish that a twinning model was refined.   
#=============================================================================
# >>> Test for (in)commensurate structure based CIF   
_814    0    0    0 5 A   0 0 0 1   
No Validation of (In)commensurate Structure CIFs            Note

 PLATON/CheckCIF can not validate the CIFs associated with (in)commensurate 
 structure reports. 
#=============================================================================
# >>> Test for number of population parameter overflow in PLATON
_815    0    0    0 5 A   0 0 0 1
PLATON Issue: Population Parameter Overflow ....            Fatal

 PLATON/checkCIF is currently dimensioned for up to 255 population parameters.
 Please contact the author at a.l.spek@uu.nl
#=============================================================================
# >>> Test for final refinement with detwinned 'HKLF 4' data
_816    0    0    0 5 A   0 0 0 1   
Likely Final Refinement with Detwinned Data ....  $A Check   

 The CIF includes a loop with twin matrices. The embedded .res file however
 points to a HKLF 4 file with likely detwinned intensities. 
#=============================================================================
# >>> Report read problem in PLATON checkCIF routine
_820    0    0    0 5 A   0 0 0 1   
Internal PLATON Read Problem with ALERT Number .  $A

 Internal PLATON Problem. Please refer problem to author at a.l.spek@uu.nl  
#=============================================================================
# >>> Check for negative PART record(s) in CIF-embedded .res file   
_822    0    0    0 4 A   0 0 0 1   
CIF-embedded .res Contains Negative PART Numbers $I Check   

 Please check the validity of the negative PART numbers in the CIF-embedded 
 SHELXL .res file. Their use may obscure disorder model errors.   
#=============================================================================
# >>> Test for BASF/TWIN problem in SHELXL  
_850  0.0  2.0  2.0 4 A   0 0 0 1   
Check Flack Parameter Exact Value 0.00 with s.u. $F Check   

 This G_ALERT can be ignored in the case that the so-called 'on-the-cheap'  
 Flack parameter is reported as determined with SHELXL. 

 Exactly zero values are possible but may also be a software artefact.  

 The following should be checked:   

 Problem #1: Some SHELXL97 versions do not allow negative values of the 
 Flack parameter when determined using the BASF/TWIN instructions.  
 Negative values are set to 0.00001. Refinement may not converge completely.

 Problem #2: Some SHELXL97 versions put meaningless values in the CIF for the   
 Flack parameter when 'TWIN -1 0 0 0 -1 0 0 0 -1 2 / BASF' instructions (i.e.   
 an explicit matrix is specified on the TWIN instruction) are used. 
 Please check the value of BASF (in the list output)  against the Flack 
 parameter in the CIF. 	
#=============================================================================
# >>> Test for restraints being used in refinement
_860    0    0    0 3 I   0 0 1 0   
Number of Least-Squares Restraints ............. $I Note

 The use of restraints used in the refinement should be explained in
 the write-up of a structure analysis.  

 It is also recommended to include the refinement instructions in the   
 CIF (e.g. the final .res of a SHELXL refinement) as a comment: 
 _iucr_refine_instructions_details  
 ;  
 TITL   
 .. 
 (etc.) 
 ;  

 Note: An exception are restraints for floating origins (e.g. in P21).  
#=============================================================================
# >>> Notify the suppression of Olex2/_smtbx_masks related ALERTS   
_868    0    0    0 4 A   0 0 0 1   
ALERTS Due to the Use of _smtbx_masks Suppressed          ! Info

 ALERTS related to the use of Olex2/_smtbx_masks that can not (yet) be  
 accounted for as part of the VALIDATION algorithms have been suppressed.   
#=============================================================================
# >>> Notify the suppression of SQUEEZE related ALERTS  
_869    0    0    0 4 A   0 0 0 1   
ALERTS Related to the Use of SQUEEZE  Suppressed          ! Info

 ALERTS related to the use of PLATON/SQUEEZE that can not (yet) be accounted
 for as part of the VALIDATION algorithms have been suppressed. 
#=============================================================================
# >>> Report the suppression of some twinning related ALERTS
_870    0    0    0 4 A   0 0 0 1   
ALERTS Related to Twinning Effects Suppressed ..          ! Info

 ALERTS related to twinning effects that can not (yet) be accounted 
 for as part of the VALIDATION algorithms have been suppressed. 
#=============================================================================
# >>> Report the suppression of some Laue technique related ALERTS  
_871    0    0    0 4 A   0 0 0 1   
Laue Technique Related ALERTS are Suppressed ...          ! Info

 ALERTS related to the use of the Laue technique with a wavelength  
 range have been suppressed.
#=============================================================================
# >>> Report the suppression of anharmonic refinement related ALERTS
_872    0    0    0 4 A   0 0 0 1   
ALERTS Related to Anharmonic Refine   Suppressed          ! Info

 ALERTS related to anharmonic refinement have been suppressed. This generally   
 concerns XD and some OLEX2 refinement based CIF's. Internally calculated   
 structure factors are based on the reported harmonic displacement parameters   
 only.  
#=============================================================================
# >>> Report missing datum for _diffrn_reflns_number
_880    0    0    0 1 A   1 0 0 0   
No datum for _diffrn_reflns_number supplied ....     Please Do !

 The total number of measured reflections is not reported.  
#=============================================================================
# >>> Report missing datum for _diffrn_reflns_av_R_equivalents  
_881    0    0    0 1 A   1 0 0 0   
No Datum for _diffrn_reflns_av_R_equivalents ...     Please Do !

 The merging R-factor for equivalent reflections is missing in the CIF. 
 A value of 0.0 usually indicates that merging has been done outside the
 program that created the CIF. A proper value should be included as reported
 by the external merging program. Note: modern hardware will generally produce  
 redundant reflection data. 
#=============================================================================
# >>> Report missing datum for _diffrn_reflns_av_unetI/netI
_882    0    0    0 1 A   1 0 0 0   
No Datum for _diffrn_reflns_av_unetI/netI ......     Please Do !

 No value reported for either _diffrn_reflns_av_unetI/netI or the   
 older/superseded _diffrn_reflns_av_sigmaI/netI CIF item.   
#=============================================================================
# >>> Report missing datum for _atom_sites_solution_primary 
_883    0    0    0 1 I   1 0 0 0   
No Info/Value for _atom_sites_solution_primary .     Please Do !

 Please supply the proper info for _atom_site_solution_primary. Values must 
 be one of the following: difmap, vecmap, heavy, direct, geom, disper, isomor,  
 notdet, dual, iterative, other.
#=============================================================================
# >>> Check for duplicate H-M space group symbol
_898  0.0  0.0  0.0 4 A   0 0 0 1   
Second Reported H-M Symbol in CIF Ignored ......          ! Check   

 A second specification of the H-M symbol is found in the CIF. Only the 
 first one encountered is retained. 
#=============================================================================
# >>> Report the Use of an older SHELXL version 
_899    0    0    0 4 A   0 0 0 1   
$B is Outdated   and Succeeded by SHELXL  $A Note

 A more recent SHELXL version is now available. Final refinement with the   
 latest version is recommended since (IUCr)checkCIF is run against the latest 
 SHELXL version for the re-creation of the FCF and its validation. 
#=============================================================================
# >>> Test for 'No-matching reflection file'
_900    0    0    0 1 I   0 0 0 1   
No Matching Fo/Fc Reflection File (FCF) Found ..     Please Check   

 Likely cause: Dataset names in the CIF and FCF differ. 
 Note: FCF Validation is Skipped for this Entry.
#=============================================================================
# >>> Test for CIF & FCF CELL parameters not matching  
_901    0    0    0 1 I   0 0 0 1   
Cell Parameters in CIF and FCF do not Match ....          ! Error   

 Possible causes: wrong dataset, CIF or FCF parameters edited inconsistently
 or cell parameters for transformed cell (e.g. P21/n <-> P21/c).
 Note: FCF Validation is Skipped for this Entry.
#=============================================================================
# >>> Test for non-zero number of recognised reflections in FCF 
_902    0    0    0 1 I   0 0 0 1   
No (Interpretable) Reflections Found in FCF ....     Please Check   

 Either no reflections are found in the FCF or the FCF is uninterpretable   
 due to unknown format or editing.  
 Note: FCF Validation is Skipped for this Entry.
#=============================================================================
# >>> Test for Fobs=Fcalc in FCF
_903    0    0    0 1 I   0 0 0 1   
F(obs) and F(calc) Values are Identical in FCF .     Please Check   

 Check the FCF file for F(obs) equal F(calc) [or F(obs)**2 equal F(calc)**2].   
 The FCF is obviously not created as the result of a refinement with regular 
 observed data.
#=============================================================================
# >>> Test for Nref > Npar in the CIF
_904    0    0    0 1 I   0 0 0 1   
Number of Reflections is <  Number of Parameters $I 

 The number of reflections found in the reflection file is less than the
 number of parameters reported in the CIF.  
#=============================================================================
# >>> Report negative K values in the Analysis of Variance  
_905  0.0  1.0  2.0 3 I   0 0 1 0   
Negative K value in the Analysis of Variance ... $F Report  

 Scale Factors (i.e. K = Mean[Fo**2] / Mean [Fc**2]) for selected groups of 
 reflections, as listed in the Analysis of Variance Section #7 of the FCF   
 validation report, are expected to have a value of about 1.000. Strong 
 deviations should be investigated, acted upon or explained.
 (see also SHELXL manual). A reason can be meaningless (weak) high order
 data where a cut-back of the resolution might be indicated. Incorrect  
 background treatment can lead to numerous negative observed intensities
 for weak reflections (i.e. F(calc) close to zero.  
 For details see the Analysis-of-Variance Section in the '.ckf' file.   
#=============================================================================
# >>> Report Large K values in the Analysis of Variance 
_906  0.0  1.0  2.0 3 I   0 0 1 0   
Large K Value in the Analysis of Variance ...... $F Check   

 Scale Factors (i.e. K = Mean[Fo**2] / Mean [Fc**2]) for selected groups of 
 reflections, as listed in the Analysis of Variance Section #7 of the FCF   
 validation report, are expected to have a value of about 1.000. Strong 
 deviations should be investigated, acted upon or explained. (see also SHELXL
 manual). For details see the Analysis-of-Variance Section in the '.ckf' file.   
#=============================================================================
# >>> Check whether the structure needs to be inverted  
_907  0.5 10.0 10.0 2 A   0 0 1 0   
Flack x > 0.5, Structure Needs to be Inverted? . $F Check   

 A Flack x value generally indicates that the structure needs to be inverted.   
 Check whether the Flack x value is unreliable due to a weak anomalous
 dispersion signal, systematic errors or weak data and against know absolute
 structure. 

#=============================================================================
# >>> Report on Max observed data in any resolution shell   
_908    0    0    0 2 A   0 0 0 1   
Max. Perc. Data with I > 2*s(I) per Res.Shell . $F% Note

 A low maximum percentage of reflections with I > 2*s(I) may indicate:  
 1 - Missed translation symmetry. E.g. all reflections hkl weak 
     for l = 2n +1  
 2 - Pseudo-merohedral twinning, index > 1. (e.g. non-spacegroup
     extinctions.   
 3 - Very weak observed data.   
#=============================================================================
# >>> Report about significant observed data beyond Theta-cutoff   
_909    0    0    0 3 A   0 1 0 0   
Percentage of I>2sig(I) Data at Theta(Max) Still$I% Note

 This ALERT Reports on whether there is still a significant level of
 observed data beyond the Theta cutoff of the Dataset. There should 
 be a good reason for a cutoff below sin(theta)/lambda = 0.6.   
 Reflection data beyond that value should not be removed when significantly 
 above the noise level. E.g. they may be very relevant in case of pseudo-   
 symmetry and (non)centrosymmetry refinement.   
#=============================================================================
# >>> Test for number of missing reflections below Theta(Min) 
_910    0   10   50 3 A   0 0 0 1   
Missing # of FCF Reflection(s) Below Theta(Min). $I Note

 Possible causes: Experimental beamstop Theta(min) limit set too high; A large
 unit-cell causing reflections effected by the beamstop. A possible technical
 solution on CCD based equipment involves the collection of additional images
 with the detector at a larger distance from the crystal with the beamstop 
 setting changed accordingly. Alternatively, a large number of low-order
 'outlier' reflections might have been 'Omitted' deliberately from the (final)
 least-squares refinement. The test is against the actual Theta(Min) of the
 reflections in the *.fcf file. See the *.ckf file for details of the missing
 reflections. Good quality low order reflections might be relevant for SQUEEZE
 and similar solvent modelling refinement techniques.
#=============================================================================
# >>> Test for missing reflections between Theta(Min)and Sin(Theta)/Lambda=0.6  
_911   -1    5  999 3 A   0 0 0 1   
Missing FCF Refl Between Thmin & STh/L=$A $I Report 

 Possible causes: Missing cusp of data (due to rotation about one axis),
 deleted (overflow) reflections or improper strategy (orthorhombic for  
 monoclinic crystal etc.) See the .ckf file for details.
#=============================================================================
# >>> Test for missing reflections above Sin(Theta)/Lambda = 0.6   
_912   -1  100  999 4 A   0 0 0 1   
Missing # of FCF Reflections Above STh/L=  0.600 $I Note

 Possible causes: Missing cusp of data (due to rotation about one axis),
 deleted (overflow) reflections or improper strategy (orthorhombic for  
 monoclinic crystal etc.) See the .ckf file for details.
#=============================================================================
# >>> Test for missing strong reflections   
_913    0  100  999 3 A   0 0 0 1   
Missing # of Very Strong Reflections in FCF .... $I Note

 This ALERT reports the number of missing reflections with Fc**2 values 
 greater than the largest Fc**2 value in the FCF. Possible causes: Missing  
 cusp of data (due to rotation about one axis), deleted (overflow)  
 reflections or improper strategy (orthorhombic for monoclinic crystal etc.)
 or behind the beamstop. See the .ckf file for details. 
#=============================================================================
# >>> Test for absence of Bijvoet Pairs in non-centro structure 
_914    0    2    2 3 A   0 0 0 1   
No Bijvoet Pairs in FCF for Non-centro Structure     Please Check   

 This ALERT reflects the notion that a dataset should contain a sufficient  
 number of Bijvoet (Friedel) pairs for the reliable determination of the
 absolute structure of a non-centrosymmetric crystal structure. 
 This test is invoked when a Flack parameter value is specified.
 Note: SHELXL97 will calculate/report a Flack parameter value even for  
 refinement against Friedel merged data. Remove the Flack entry from the CIF.
#=============================================================================
# >>> Test for low Friedel pair coverage in non-centro structure
_915  20.  50.  100 3 A   0 0 0 1   
No Flack x Check Done: Low Friedel Pair Coverage $I %   

 This ALERT reflects the notion that a dataset should contain a sufficient  
 number of Bijvoet (Friedel) pairs for the reliable determination of the
 absolute structure of a non-centrosymmetric crystal structure. 

 A Friedel coverage that deviates significantly from 100 percent may
 bias/invalidate the value of the Flack parameter.  
#=============================================================================
# >>> Test for differing Flack x and Hooft y parameter values   
_916  0.1  0.2  0.3 2 A   0 0 0 1   
Hooft y and Flack x Parameter Values Differ by . $F Check   

 The Hooft y Parameter is calculated independently from the Bijvoet 
 differences and should have a value similar (observing the s.u.'s) to that of  
 the Flack x Parameter. See: Hooft, R.W.W, Straver, L.H. & Spek,A.L. (2008).
 J. Appl, Cryst. 41, 96-103. Thompson,A.L. & Watkin, D.J. (2009). Tetrahedron:
 Asymmetry, doi:10.1016/j.tetasy.2009.02.025 
 Large differences may arise in cases where the Flack parameter was not 
 determined with a BASF/TWIN refinement or with essentially centrosymmetric
 data. See: Flack, H.D., Bernardinelli, G, Clemente, D.A., Linden, A. Spek,
 A.L. (2006) Acta Cryst. B62, 695-701.  
#=============================================================================
# >>> Test/report whether FCF is based on a BASF/TWIN refinement
_917  0.0  0.0  0.0 2 A   0 0 0 1   
The FCF is Likely NOT Based on a BASF/TWIN Flack     Please Check   

 The contribution of F(-h,-k,-l) to F(h,k,l) is likely not included in the  
 FCF file. This usually indicates that the Flack parameter was NOT determined   
 with a BASF/TWIN type of refinement.   
#=============================================================================
# >>> Test for reflections with I(obs) << I(calc)   
_918    0  999  999 3 A   0 0 0 1   
Reflection(s) with I(obs) much Smaller I(calc) . $I Check   

 This ALERT reports on the number of reflections with   
 (Fo**2 - Fc**2) / Sigma(Fo**2) < - 100.0. In case of strong reflections this   
 might be due to extinction (to be addressed with the refinement of an  
 extinction parameter. Otherwise Those reflections are better removed from the  
 final refinement since they are in systematic error. Of course, a valid
 reason for this problem should be found.
#=============================================================================
# >>> Test for reflections affected by the beamstop 
_919    0    0  999 3 A   0 0 0 1   
Reflection # Likely Affected by the Beamstop ... $I Check   

 This ALERT reports the number of reflections with intensities seriously
 effected by the beamstop. Reflections are counted for which theta < 3  
 Degrees and (Fo**2 - Fc**2) / sqrt(weight) < - 10.0. Those reflections 
 are better removed from the final refinement since they are in systematic  
 error. 
#=============================================================================
# >>> Test for Theta(Max) consistency between CIF & FCF
_920  .10  .50 99.0 1 A   0 0 0 1   
Theta(Max)  in CIF and FCF Differ by ........... $F Degree  

 Check reflection statistics of the data in the FCF for consistency with
 the data reported in the CIF. A difference usually indicates an edited CIF or
 an FCF file that was not created in the same SHELXL run where the CIF was
 created. In rare cases this ALERT may point to using a SHELXL TWIN 
 instruction for handling a non-merohedral twin. 
#=============================================================================
# >>> Test for R1 Consistency between CIF & FCF(Reported)   
_921 .001 .005 .050 1 A   0 0 0 1   
R1  in the CIF and FCF Differ by ............... $F Check   

 Please check whether the supplied FCF corresponds with the CIF produced in 
 the same least squares refinement job. See at the end of Section #10 in the
 .ckf report file for details. The test is based on the observed and
 calculated F**2 in the FCF and de weight parameters taken from the CIF.  
#=============================================================================
# >>> Test for wR2 consistency between CIF & FCF(Reported)  
_922 .001 .005 .050 1 A   0 0 0 1   
wR2 in the CIF and FCF Differ by ............... $F Check   

 Please check whether the supplied FCF corresponds with the CIF produced in 
 the same least squares refinement job. See at the end of Section #10 in the
 .ckf report file for details. The test is based on the observed and
 calculated F**2 in the FCF and de weight parameters taken from the CIF.  
#=============================================================================
# >>> Test for S consistency between CIF & FCF(Reported)
_923  .01  .50  1.0 1 A   0 0 0 1   
S    Values in the CIF and FCF Differ by ....... $F Check   

 Please check whether the supplied FCF corresponds with the CIF produced in 
 the same least squares refinement job. See at the end of Section #10 in the
 .ckf report file for details. The test is based on the observed and
 calculated F**2 in the FCF and de weight parameters taken from the CIF.  
#=============================================================================
# >>> Test for consistency of the reported & calculated  Rho(min)  
_924  1.0  2.0  3.0 1 A   0 0 0 1   
The Reported and Calculated Rho(min) Differ by . $F eA-3

 Check & Explain why the Reported Rho(min) differs significantly from the  
 value calculated on the basis of the reported structure (using the AIM model)  
 Note: The Reported and Calculated values may differ slightly due to a
 differing peak interpolation algorithm, or significantly when the refinement
 is based on a non-spherical atom model.  
#=============================================================================
# >>> Test for consistency of the reported & calculated Rho(max)   
_925  1.0  2.0  3.0 1 A   0 0 0 1   
The Reported and Calculated Rho(max) Differ by . $F eA-3

 Check & Explain why the Reported Rho(max) differs significantly from the  
 value calculated on the basis of the reported structure (using the AIM model)  
 Note: The Reported and Calculated values may differ slightly due to a
 differing peak interpolation algorithm, or significantly when the refinement
 is based on a non-spherical atom model.  
#=============================================================================
# >>> Test for R1 consistency between CIF & FCF(Calculated) 
_926 .001 .005 .050 1 A   0 0 0 1   
Reported and Calculated   R1 Differ by ......... $F Check   

 Please check whether the R1 value that is reported in the CIF corresponds  
 with the R1 value calculated from the parameters supplied in the CIF. See at
 the end of Section #10 in the .ckf report file for details.  This test is
 based on the observed reflection data in the FCF and reflection data that are
 calculated with the parameters (i.e. coordinates, displacement and weight
 parameters) taken from the CIF.
#=============================================================================
# >>> Test for wR2 consistency between CIF & FCF(Calculated)
_927 .001 .005 .050 1 A   0 0 0 1   
Reported and Calculated  wR2 Differ by ......... $F Check   

 Please check whether the wR2 value that is reported in the CIF corresponds 
 with the wR2 value calculated from the parameters supplied in the CIF. See at 
 the end of Section #10 in the .ckf report file for details.  This test is
 based on the observed reflection data in the FCF and reflection data that are
 calculated with the parameters (i.e. coordinates, displacement and weight
 parameters) taken from the CIF.
#=============================================================================
# >>> Test for S consistency between CIF & FCF(Calculated)  
_928  .10  .20 2.00 1 A   0 0 0 1   
Reported and Calculated    S value   Differ by . $F Check   

 Please check whether the S value that is reported in the CIF corresponds   
 with the S value calculated from the parameters supplied in the CIF.   
 See at the end of Section #10 in the .ckf report file for details. 
 This test is based on the observed reflection data in the FCF and  
 reflection data that are calculated with the parameters (i.e. coordinates, 
 displacement and weight parameters) taken from the CIF.
#=============================================================================
# >>> Test for interpretable weight parameters for R1, wR2 & S comparison
_929    0   10   10 5 A   0 0 0 1   
No Weight Pars,Obs and Calc R1,wR2,S not Checked          ! Info

 SHELXL weight parameters are expected to be given in the format below: 

 _refine_ls_weighting_details   
 'calc w=1/[\s^2^(Fo^2^)+(0.1000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'

 JANA style weight is expected to be given in the format:   

 _refine_ls_weighting_details 'w=1/(\s^2^(I)+0.0016I^2^)'   

  Do not edit this string or make it into a text block between ';'. 
#=============================================================================
# >>> Test for missed twinning based on the analysis of the FCF data
_930  .00  .00  .80 2 A   0 0 1 0   
FCF-based   Twin Law$A$BEst.d BASF $F Check 

 Check the proposed Twin Law. The entry in () represents the proposed rotation
 axis in reciprocal space and the one in [] the corresponding rotation is
 direct space. The relevant Twin Matrix can be found in the file '.ckf'.  
 Note: This analysis is based on Fobs**2/Fcalc**2 differences with Fcalc**2 
 data taken from the .fcf file (i.e. Fobs, Fcalc listing).   
 ALERT-930 is expected to generate an related ALERT-931 as well.
#=============================================================================
# >>> Test for missed twinning from FCF/CIF data
_931  .00  .00  .80 5 A   0 0 1 0   
CIFcalcFCF  Twin Law$A$BEst.d BASF $F Check 

 Check the proposed Twin Law. The entry in () represents the proposed rotation
 axis in reciprocal space and the one in [] the corresponding rotation is
 direct space. The relevant Twin Matrix can be found in the file '.ckf'.  
 Note: This test is based on Fcalc**2 values calculated with the data in the
 CIF. This ALERT can be ignored when twinning has been addressed in the
 refinement (As indicated by the Absence of ALERT 930). Please make sure that
 twinning is mentioned in the write-up of the structure report and paper. 
#=============================================================================
# >>> Report number of OMIT records in embedded .res file
_933    0    0    0 2 A   0 0 1 0   
Number of HKL-OMIT Records in Embedded .res File $I Note

 This ALERT reports on the number of 'OMIT h k l' records (Reflections
 omitted from the least-squares refinement) in the CIF embedded .res file.
 Generally, there should be a good reason for excluding those observed
 experimental data point such as (partial) obscuration by the beam stop. 
#=============================================================================
# >>> Report number of outliers in the FCF file 
_934    0    1   10 3 A   0 0 1 0   
Number of (Iobs-Icalc)/Sigma(W) > 10 Outliers .. $I Check   

 This ALERT reports on the number of reflections for which I(obs) and I(calc)   
 differ more that 10 times SigmaW. (The latter being the square root of 
 1.0/weight for that reflection in the L.S. refinement). The reason for those   
 deviations should be investigated. When shown to be systematic errors, those
 reflections are best removed from the refinement and their omission from the
 refinement reported in the experimental section of an associated paper. 
#=============================================================================
# >>> Pseudo extinction parameter test  
_935  .05 1.00 2.00 2 A   0 0 0 0   
Large Value of Calc. Pseudo Extinction Parameter $F 

 Both significantly positive and significantly negative values should   
 invoke a search for a likely cause and a corrective action.
#=============================================================================
# >>> Test for DAMP instruction in embedded .res file
_936    0  0.5    1 2 A   0 0 1 0   
The Embedded .res File Includes a DAMP Command . $F Report  

 The reason for the use of a DAMP instruction in the final refinement job   
 should be discussed/reported. 'DAMP 0.0' should not be used for small  
 molecule refinement since it masks non-convergence.
#=============================================================================
# >>> Report exponential term in SHELXL weight expression   
_937    0 10.0 20.0 4 A   0 0 1 0   
Weight Expression Contains Exponential Term .... $F Report  

 The use of an exponential term in the SHELXL weight expression is not  
 recommended in the final refinement stage (i.e. the third parameter in the 
 SHELXL WGHT record).   
#=============================================================================
# >>> Test for high not weight optimized S value
_939 10.0 100. 500. 3 A   0 0 0 1   
Large Value of Not (SHELXL) Weight Optimized S . $F Check   

 SHELXL suggests/optimizes two weight parameters aiming at bringing the S
 value (Goodness-of-Fit) close to 1.0. This 939_ALERT reports the S value when
 based on the supplied sigma(I) values only. A large value of this not weight
 optimized S generally indicates the presence of large outliers in the data
 set. Examples are reflections (partially) 'measured' behind the beam stop.
 (See also ALERT_919). The latter low order reflections are best left out from 
 the final refinement with an OMIT hkl instruction.  
#=============================================================================
# >>> Test for wR2 refinement with all data 
_940    0    0    2 3 A   0 0 0 1   
Fsqd Refinement With I > n * Sigma(I) Only .....     Please Check   

 Apparently, observed data with I > n * sigma(I) were used in the F**2  
 least squares refinement, rather than all observed data. Please ignore
 when the dataset is essentially complete (and all reflections used in the
 refinement 'observed'.    
#=============================================================================
# >>> Test for low measured hkl multiplicity
_941  0.0  5.0  5.0 3 A   0 1 0 0   
Average HKL Measurement Multiplicity ........... $F Low 

 Multiple hkl measurements are advised, either of symmetry related reflections  
 and/or at different psi angle values around the diffraction vector normal to
 the diffracting plane. A good multiplicity is needed for a meaningful  
 multi-scan based correction for absorption. Details can be found in the .ckf
 file.  
#=============================================================================
# >>> Test for Poisson type intensity sigma distribution
_949    0    0    0 5 A   0 1 0 0   
Unusual Experimental Reflection Sigma(I)'s .....     Please Check   

 Check the validity of the observed reflection data.
#=============================================================================
# >>> Test for reported and calculated Hmax difference (from CIF data)  
_950    0  100  200 5 I   0 0 0 1   
Calculated (ThMax) and CIF-Reported Hmax Differ  $I Units   

 Reported (in the CIF) and Calculated (from Theta-max in CIF) Max(Hmax,-Hmin)   
 values differ by at least one unit. Check the consistency of wavelength and
 reported resolution data items.
#=============================================================================
# >>> Test for reported and calculated Kmax difference (from CIF data)  
_951    0  100  200 5 I   0 0 0 1   
Calculated (ThMax) and CIF-Reported Kmax Differ  $I Units   

 Reported (in the CIF) and Calculated (from Theta-max in CIF) Max(Kmax,-Kmin)   
 values differ by at least one unit. Check the consistency of wavelength and
 reported resolution data items.
#=============================================================================
# >>> Test for reported and calculated Lmax difference (from CIF Data)  
_952    0  100  200 5 I   0 0 0 1   
Calculated (ThMax) and CIF-Reported Lmax Differ. $I Units   

 Reported (in the CIF) and Calculated (from Theta-max in CIF)  Max(Lmax,-Lmin)  
 values differ by at least one unit. Check the consistency of wavelength and
 reported resolution data items.
#=============================================================================
# >>> Test for reported (in CIF) and actual Hmax difference in the FCF File 
_953    1  999  999 1 I   0 0 0 1   
Reported (CIF) and Actual (FCF) Hmax Differ by . $I Units   

 Reported (in the CIF) and Actual (in the FCF)  Max(Hmax,-Hmin) values differ  
 by more than one unit. Check for data set truncation.   
#=============================================================================
# >>> Test for reported (in CIF) and actual Kmax difference in the FCF File 
_954    1  999  999 1 I   0 0 0 1   
Reported (CIF) and Actual (FCF) Kmax Differ by . $I Units   

 Reported (in the CIF) and Actual (in the FCF) Max(Kmax,-Kmin) values   
 differ by more than one unit. Check for data set truncation.   
#=============================================================================
# >>> Test for reported (in CIF) and actual Lmax difference in the FCF file 
_955    1  999  999 1 I   0 0 0 1   
Reported (CIF) and Actual (FCF) Lmax Differ by . $I Units   

 Reported (in the CIF) and Actual (in the FCF) Max(Lmax,-Lmin) values   
 differ by more than one unit. Check for data set truncation.   
#=============================================================================
# >>> Test for calculated (Theta-max) and actual Hmax difference in the FCF
_956    1  999  999 1 I   0 0 0 1   
Calculated (ThMax) and Actual (FCF) Hmax Differ  $I Units   

 Calculated (From Theta-Max in the CIF) and Actual (in the FCF) Max(Hmax,-Hmin) 
 values differ by more than one unit. Check for data set truncation.
#=============================================================================
# >>> Test for calculated (Theta-max) and actual Kmax difference in the FCF 
_957    1  999  999 1 I   0 0 0 1   
Calculated (ThMax) and Actual (FCF) Kmax Differ  $I Units   

 Calculated (From Theta-Max in the CIF) and Actual (in the FCF) Max(Kmax,-Kmin) 
 values differ by more than one unit. Check for data set truncation.
#=============================================================================
# >>> Test for calculated (Theta-max) and actual Lmax difference in the FCF 
_958    1  999  999 1 I   0 0 0 1   
Calculated (ThMax) and Actual (FCF) Lmax Differ. $I Units   

 Calculated (From Theta-max in the CIF) and Actual (in the FCF) Max(Lmax,-Lmin) 
 values differ by more than one unit. Check for data set truncation.
#=============================================================================
# >>> Test for reflections with I < -2*sigma(I)  
_960    0    0  999 3 A   0 0 0 1   
Number of Intensities with I < - 2*Sigma(I) .... $I Check   

 Multiple strongly negative intensities may be indicative for poor integration
 of the  diffraction images. Too many negative intensities may result in
 higher than usual wR2 values.  
#=============================================================================
# >>> Test for absence of negative observed intensities 
_961    0    0    0 5 A   0 0 0 1   
Dataset Contains no Negative Intensities .......     Please Check   

 Generally, both positive and slightly negative intensities are expected in a
 data set. Resetting negative intensities to zero may bias the refinement
 results and the 'analysis-of-variance' as reported e.g. in the  SHELXL output
 listing. 
#=============================================================================
# >>> Test for input reflections with Sigma(I) = 0.0 
_962    0    0    1 5 A   0 0 0 1   
Number $A  Relections with Sigma(I) = 0.0 $I Note 

 Reflections with Sig(I) = 0.0 are suspect and best left out of the  
 refinement. This type of reflections will result in multiple R & S-value
 difference ALERTS. Note: Sometimes such a 0.00 value may be related to the
 limited number of reported decimals in the FCF file as opposed to those in 
 the unscaled unmerged HKL file.
#=============================================================================
# >>> Test for both weighting parameter values zero (SHELXL)
_963  0.0  0.0  0.0 2 A   0 0 0 1   
Both SHELXL WEIGHT Parameter Values Zero .......     Please Check   

 Check unusual reported/refined zero SHELXL weight parameter values.
 Note: SHELXL will not refine to negative values.   
#=============================================================================
# >>> Test for consistency of SHELXL weight parameters in CIF & embedded .res 
_964  0.0  0.0  1.0 2 A   0 0 0 1   
SHELXL WEIGHT Par. Values in CIF & RES Differ ..     Please Check   

 Two weight parameter values reported in the CIF weight expression string
 (_refine_ls_weighting_details) are found to differ from those archived in the
 WGHT parameter value list in the embedded RES file. The latter values are
 assumed to be the correct ones as part of the final refinement. 
 Recreation of the FCF from the embedded .ins & .hkl will result in
 inconsistent wR2 and S values and associated ALERTS in the checkCIF report
 when those weight parameter values differ. Please also check the proper
 format of the SHELXL weight expression string.
#=============================================================================
# >>> Test whether the SHELXL weight optimisation has converged 
_965  0.0  0.0  0.0 2 A   0 0 0 1   
The SHELXL WEIGHT Optimisation has not Converged     Please Check   

 Additional refinement cycles are advised using the (SHELXL) suggested new   
 WGHT parameter values. 
#=============================================================================
# >>> Test/report OMIT threshold criterium value
_966    0    0    0 5 A   0 0 0 1
Note: Non-Standard (i.e. 2.0) OMIT Threshold  of $F Sig(I)
 
 The conventional OMIT threshold is I>2\s(I). This ALERT reports the use of
 a deviating value effecting e.g. the reported R1 value.
#=============================================================================
# >>> Report theta cutoff (OMIT) record in embedded .res
_967    0    0    0 5 A   0 0 0 1
Note: Two-Theta Cutoff Value in Embedded .res .. $F Degree
 
 In general refinement with all experimental reflection data is advised. A
 theta value cutoff may be considered to avoid refinement on noise for
 resolution shells with <I/sigma> < 2*sigma. 
#=============================================================================
# >>> Report 'Henn et al.' predicted and R-factor-gap values
_969    0    0    0 5 A   0 0 0 1
The 'Henn et al.' R-Factor-gap value ........... $F Note
  
 Report on predicted wR2, based on counting statistics, or SHELXL style
 weighting as compared to the actual refined wR2.
 See: J.Henn & A.Schonleber, Acta Cryst. (2013) A69, 549-558.
#=============================================================================
# >>> Test/report electron diffraction data 
_970    0    0    0 5 A   0 0 0 1   
Refinement Requires Electron Scattering Factors      Please Check   

 A structure based on electron diffraction is reported. 
 Please check for the use of proper electron scattering factors in the  
 refinement. X-ray scattering factors are not appropriate for a SHELXL based
 refinement.
#=============================================================================
# >>> Test for large positive calculated residual density   
_971 1.50 2.50 3.50 2 A   0 0 1 0   
Check Calcd Resid. Dens.$B From $A $F eA-3  

 Larger than expected residual density maximum outside metal atom locations.
 This might be caused by unaccounted for twinning, wrongly assigned atom
 types, unaccounted for solvent and other model errors.
 Note: This value is based on an AIM calculation and may differ significantly
 for a refinement using a non-spherical atom model.
#=============================================================================
# >>> Test for large negative calculated residual density   
_972 1.50 2.50 3.50 2 A   0 0 1 0   
Check Calcd Resid. Dens.$B From $A $F eA-3  

 Larger than expected residual density minimum outside metal atom locations.
 This might be caused by unaccounted for twinning, wrongly assigned atom
 types and other model errors. 
 Note: This value is based on an AIM calculation and may differ significantly
 for a refinement using a non-spherical atom model.
#=============================================================================
# >>> Test for large positive density on metal atom 
_973 1.00  1.5  2.0 2 A   0 0 1 0   
Check Calcd Positive Resid. Density on $A $F eA-3   

 Larger than expected residual density maximum on metal atom location.  
 This might be caused by unaccounted for twinning, wrongly assigned 
 atom types and other model errors. Another cause may be a SHELXL 'DAMP 0 0'
 instruction for a non-converged refinement.
#=============================================================================
# >>> Test for large negative density close to metal atom   
_974 1.00  1.5  2.0 2 A   0 0 1 0   
Check Calcd Negative Resid. Density on $A $F eA-3   

 Larger than expected residual density minimum on metal atom location. This  
 might be caused by unaccounted for twinning, wrongly assigned atom types 
 and other model errors. Another cause may be a SHELXL 'DAMP 0 0' instruction
 for a non-converged refinement.
#=============================================================================
# >>> Test for positive density near N or O 
_975 0.30  1.5  2.0 2 A   0 0 1 0   
Check Calcd Resid. Dens.$B From $A $F eA-3  

 Positive density found in a difference density map at a position within
 bonding distance for a H-atom from a nitrogen or oxygen atom. A
 possible reason can be a missing hydrogen atom. Also check for tautomerism.
#=============================================================================
# >>> Test for negative density near N or O 
_976 0.30  1.5  2.0 2 A   0 0 1 0   
Check Calcd Resid. Dens.$B From $A $F eA-3  

 Negative density found in a difference density map at a location within   
 bonding distance for a H-atom from a nitrogen or oxygen atom. A possible 
 reason can be a misassigned H-atom. Also check for tautomerism.
#=============================================================================
# >>> Test for negative density on H-atom positions 
_977 0.30  1.5  2.0 2 A   0 0 1 0   
Check Negative Difference Density on $A . $F eA-3   

 Negative density found in a difference density map at a H-atom location.   
 A reason might be an incorrect AFIX instruction.   
#=============================================================================
# >>> Report number of cases with positive density on C-C bonds 
_978    0    2    2 2 A   0 0 1 0   
Number C-C Bonds with Positive Residual Density. $I Info

 Difference density maps generally show residual densities on C-C bonds.
 A significant number of those may indicate good data. Cases where this number
 is zero should be investigated for a reason. The use of aspherical scattering
 factors in the refinement model may be one.  
#=============================================================================
# >>> Report the use of NoSpherA2 scattering factors
_979    0    0  999 1 A   0 0 0 1
NoSpherA2 Scattering Factors Used ..............     Please Note

 Non-spherical scattering factors were used in the refinement. Some ALERTS 
 that assume spherical scattering factors are suppressed. 
#=============================================================================
# >>> Test for non-zero number of anomalous scattering factors  
_980    0    0  999 1 A   0 0 0 1   
No Anomalous Scattering Factors Found in CIF ...     Please Check   

 Check for missing anomalous scattering factors.
#=============================================================================
# >>> Test for non-zero f" anomalous scattering factor values   
_981    0    0  999 1 A   0 0 0 1   
No non-zero f" Anomalous Scattering Values Found     Please Check   

 Check for non-zero f" anomalous scattering factor values in the CIF.   
 Note: Zero values are correct for SHELXL MERG 4 refinements.   
#=============================================================================
# >>> Test the anomalous scattering factor f' values against Int. Tables 
_982    0    0  999 1 A   0 0 0 1   
The$A$F Deviates from  IT-value =    $B Check   

 Check the supplied anomalous scattering factor f' value against the    
 International Tables tabulated value.   
#=============================================================================
# >>> Test the anomalous scattering factor f" values against Int. Tables 
_983    0    0  999 1 A   0 0 0 1   
The$A$F Deviates from  IT-Value =    $B Check   

 Check the supplied anomalous scattering factor f'' value against the 
 International Tables tabulated value.   
#=============================================================================
# >>> Test the anomalous scattering factor f' value against Brennan & Cowan
_984    0    0  999 1 A   0 0 0 1   
The$A$F Deviates from the B&C-Value  $B Check   

 Check the supplied anomalous scattering factor f' value for the non
 CuKa, GaKa, MoKa, AgKa, InKa wavelength against those of Brennan & Cowan. 
#=============================================================================
# >>> Test the anomalous scattering factor f" value against Brennan & Cowan
_985    0    0  999 1 A   0 0 0 1   
The$A$F Deviates from the B&C-Value  $B Check   

 Check the supplied anomalous scattering factor f'' value for the non   
 CuKa, GaKa, MoKa, AgKa, InKa wavelength against those of Brennan & Cowan.
#=============================================================================
# >>> Test for non-zero f' anomalous scattering factor values   
_986    0    0  999 1 A   0 0 0 1   
No non-zero f' Anomalous Scattering Values Found     Please Check   

 Check for non-zero f' anomalous scattering factor values in the CIF.   
#=============================================================================
# >>> Test for the need of a TWIN/BASF refinement   
_987    0  1.0  999 1 A   0 0 0 1   
The Flack x is >> 0 -  Do a BASF/TWIN Refinement     Please Check   

 A BASF/TWIN refinement of the Flack x parameter is indicated when its value
 deviates significantly from zero as measured against its associated s.u.
 value. This applies in particular for structures containing significant
 anomalous scatterers. With a default SHELXL refinement, the Flack x parameter
 value is not taken into account in the refinement model as part of the
 calculation of F(calc) and the creation of the FCF file. Inclusion of a Flack
 x in the refinement model that deviates significantly from zero will lead to
 lower R-values and a better model.  
#=============================================================================
# >>> Report the use of supplied f' for missing internaly calculated value  
_988    0    0  999 1 A   0 0 0 1   
The CIF Supplied $Avalue Used in Validation $F Note 

 Check the supplied anomalous scattering factor f' value for the reported
 wavelength. (No internally calculated f' value available).   
#=============================================================================
# >>> Report the use of supplied f'' for missing internaly calculated value 
_989    0    0  999 1 A   0 0 0 1   
The CIF Supplied $Avalue Used in Validation $F Note 

 Check the supplied anomalous scattering factor f'' value for the reported
 wavelength. (No internally calculated f'' value available).   
#=============================================================================
# >>> Report deprecated .res file based SQUEEZE job 
_990    0    0  999 1 A  0 0 0 1
Deprecated .res/.hkl Input Style SQUEEZE Job ...          ! Note

 SQUEEZE jobs should as of the availability of SHELXL20xy be based on the   
 use of a CIF+FCF created in a SHELXL20xy refinement.   
 See A.L.Spek (2015) Acta Cryst. C71, 9-18. 
#=============================================================================
# >>> Report on generated hkl data supplied as observed hkl data 
_991    0    0    0 5 A  0 0 0 1
HKL data created with PLATON/generate ..........          ! Note

 Warning that the reflection data are not experimental but calculated. Those
 data are just meant to be used as test data. 
#=============================================================================
# >>> Report difference between reported and actual _reflns_number_gt values
_992   10   50  100 5 A  0 0 0 1
Repd & Actual _reflns_number_gt Values Differ by $I Check   

 CIF Reported and actual (in FCF) '_reflns_number_gt' values are found to   
 differ. R1 values are calculated by checkCIF for cross-checking with the R1
 value as reported in the CIF. The number of 'observed' reflections that goes
 into that calculation is based on the criterium I > 2.0 * sigma(I). A 
 refinement program like SHELXL uses F(obs) > 4.0 * sigma(F(obs)) as
 'observed' criterium in its calculation of R1. Both numbers may differ
 slightly for numerical reasons. Large differences may point to
 inconsistencies between the CIF and FCF to be investigated. 
#=============================================================================
# >>> Report missing .bodd include file for IDEAL refinement  
_993    0    0  999 1 A  0 0 0 1
No .bodd Include File with BEDE & LONE records .          ! Note

 The CIF-embedded .res file includes a call for a .bodd include file. Such a
 file is not found externally or CIF-embedded. Without this file, the   
 details of the refinement are not complete and no .fcf can be created. 
#=============================================================================
# >>> Report missing SHELXL/MERG instruction
_994    0    0  999 1 A  0 0 0 1
SHELXL .ins Contains no MERG Instruction .......          ! Note

 A SHELXL job generally includes a MERG instruction. If not, the refinement 
 and 'LIST 4' FCF will include redundant reflections (i.e. refinement on more 
 than the unique set of reflections.)   
#=============================================================================
# >>> Report problem with recreating FCF with SHELXL
_995    0    0    2 1 A  0 0 0 1
Can not Recreate .fcf from Embedded  .res & .hkl          ! Check   

 There is a problem with the recreation of a .fcf file from the CIF embedded
 .res and .hkl data with SHELXL20xx. Note: SHELXL (or xl) must be in the PATH
 or set with the environment variable SHLEXE (e.g. to C:\bn\SXTL\xl.exe) 
 Please inspect the SHELXL terminal logfile for error messages. 
#=============================================================================
# >>> Test validity of SHELXL Style 'LIST 4' Fo/Fc FCF File   
_996    0    0    0 1 A   0 0 0 1   
Non-Standard SHELXL LIST 4 Style FCF Supplied ..          ! Check   

 A SHELXL 'LIST 4' Style FCF File should comply with the SHELXL Format.   
 This implies that an FCF should include only a unique set of reflections.  
 For non-centrosymmetric structures, Friedel pairs should be included.  
#=============================================================================
# >>> Test for acceptable CIF/FCF file combination for SHELXL   
_997    0    0    0 1 A   0 0 0 1   
Unsuitable CIF/FCF File Combination with SHELXL CIF       ! Error   

 The CIF file reports refinement with SHELXL whereas the supplied reflection
 file is not of the SHELXL 'LIST 4' or 'LIST 8' type. Proper FCF validation is
 not possible with the alternative LIST options.   
#=============================================================================
# >>> Test for 'LIST 3' style reflection file
_998    0    0    0 1 A   0 0 0 1   
SHELXL LIST 3 Fo/Fc Unsuitable for FCF-Validation         ! Error   

 IUCr CheckCIF validation requires SHELXL 'LIST 4', 'LIST 8' or Equivalent  
 Fo**2,Fc**2, sigma(Fo**2)  reflection files.   
#=============================================================================
# >>> Test for 'LIST 6' style reflection file 
_999    0    0    0 1 A   0 0 0 1   
SHELXL LIST 6 Fo/Fc Unsuitable for FCF-Validation         ! Error   

 IUCr CheckCIF validation requires SHELXL 'LIST 4', 'LIST 8' or equivalent  
 Fo**2,Fc**2, sigma(Fo**2) reflection files. The 'LIST 6' style file has the
 dispersion contribution removed making this file unsuitable for externel
 Analysis-of-Variance type of analysis and validation of the final refinement.  
#=============================================================================
$ END-OF-SECTION
