checkCIF procedure
PLAT881
PLAT881 Type_1 Report missing datum for _diffrn_reflns_av_R_equivalents
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.