checkCIF procedure

PLAT020

 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.