checkCIF procedure

PLAT072

 The first parameter on the SHELXL weighting line, a, used in the refinement
 has an exceptionally large value. The expected value for 'a' is less 0.1 for
 a 'good structure'. SHELXL will recommend 'WGHT 0.2 0.0' to be used in the
 next refinement when it judges the refined weight parameters values to be
 excessive. This points to a likeable problem with the reflection data and/or
 the refinement model such as improper reflection s.u.'s or an unresolved
 problem such as missed twinning.