checkCIF procedure

PLAT113

 Tests for missed symmetry are done with ADDSYM, an extended MISSYM (C) 
 clone. These tests warn for missed or possible higher (pseudo) symmetry in 
 the structural model (i.e. based on the coordinate data). Close examination
 of the situation at hand is indicated in order to prove/disprove the issue 
 (usually in combination with the reflection data). 
 Chiral molecules are incompatible with an inversion centre or (glide)planes.   
 For an example of reported pseudo-symmetry see I.A.Guzei et al, (2002).
 Acta Cryst. C58, m141-m143.
 NOTE: H-atoms and disordered atoms (i.e. atoms with population less
 than 1.0) are not taken into account in the tests. This may artificially   
 lead to a symmetry higher than the actual one. 
 NOTE: Atoms are treated as having the same atom type in order to catch 
 certain types of disorder or incorrect atom type assignment.