checkCIF procedure

PLAT012

 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.