checkCIF procedure

PLAT112

 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). This ALERT reports on
 potential additional (pseudo/real) rotation axes and mirrors.   
 In addition, (pseudo/real) lattice centering/translations are reported as  
 A, B, C, I, X, Y, Z, S. (Here S stands for special and not covered by the  
 preceding types). Full details on the situation at hand should be gleaned  
 from an actual PLATON/ADDSYM run.  
 Note: Atom types are treated in this test as EQUAL for structures with less
 than 250 atoms in the asymmetric unit in order to detect cases of misassigned
 atom types.  
 Chiral molecules are incompatible with an inversion centre or (glide)planes.   
 Note: H-atoms and disordered atoms are not taken into account in the tests.