(IUCr) Crystallography Journals Online checkcif report

[Contents scheme]

Acta Cryst. (2012). E68, o3233-o3234
[ doi:10.1107/S1600536812043619 ]

1,3-Dicyclohexylimidazolidine-2,4,5-trione: a second polymorph

O. Talhi, J. A. Fernandes, D. C. G. A. Pinto, A. M. S. Silva and F. A. Almeida Paz

Key indicators

Single-crystal X-ray study
T = 150 K
Mean (C-C) = 0.002 Å
R factor = 0.043
wR factor = 0.104
Data-to-parameter ratio = 21.4

checkCIF/PLATON results

No syntax errors found




Alert level C
PLAT369_ALERT_2_C Long   C(sp2)-C(sp2) Bond  C2     -   C3     ...       1.54 Ang.

Author Response: This bond connects two carbon atoms belonging to vicinal carbonyl groups. This feature is, in fact, a notable exception for which 1.54 Ang is indeed the typical mean value for corresponding C-C distance.

PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          6

Author Response: The data completeness is 99.8% which guarantees a correct structural elucidation of the crystal structure of the title compound.


Alert level G
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT128_ALERT_4_G Alternate Setting of Space-group P21/c   .......      P21/n      

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

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