checkCIF procedure

PLAT111

 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 with PLATON/ADDSYM is indicated in order to prove/
 disprove the issue (usually in combination with the reflection data). 
 This ALERT reports on a potential additional (pseudo/real) inversion centre.   
 A pseudo-centre may be incompatible with existing symmetry elements.   
 Chiral molecules are incompatible with an inversion centre.
 NOTE: H-atoms and disordered atoms are not taken into account in the test.