(IUCr) Crystallography Journals Online checkcif report

[Contents scheme]

Acta Cryst. (2012). E68, o1175 [ doi:10.1107/S1600536812011956 ]

4,4'-Bipyridyl-4,4'-(hydroxymethylene)dibenzoic acid (1/1)

L. Qin, L.-P. Xu and L. Han

Online 24 March 2012

Key indicators

Single-crystal X-ray study
T = 298 K
Mean (C-C) = 0.006 Å
R factor = 0.077
wR factor = 0.210
Data-to-parameter ratio = 12.8

checkCIF/PLATON results

No syntax errors found




Alert level C
DIFMX01_ALERT_2_C  The maximum difference density is > 0.1*ZMAX*0.75
            _refine_diff_density_max given =      0.675
            Test value =      0.600
DIFMX02_ALERT_1_C  The maximum difference density is > 0.1*ZMAX*0.75
            The relevant atom site should be identified.
PLAT042_ALERT_1_C Calc. and Reported MoietyFormula Strings  Differ          ?
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.45      
PLAT097_ALERT_2_C Large Reported Max.  (Positive) Residual Density       0.68 eA-3 
PLAT340_ALERT_3_C Low Bond Precision on  C-C Bonds ...............     0.0060 Ang  
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1      
              C15 H12 O5                                                       
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          5      
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600         12      

Alert level G
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT007_ALERT_5_G Note: Number of Unrefined D-H Atoms ............          1      
PLAT128_ALERT_4_G Alternate Setting of Space-group P21/c   .......      P21/n      
PLAT804_ALERT_5_G ARU-Pack Problem in PLATON Analysis ............          1 Times

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   9 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   4 ALERT level G = General information/check it is not something unexpected

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   3 ALERT type 2 Indicator that the structure model may be wrong or deficient
   3 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   3 ALERT type 5 Informative message, check