checkCIF procedure

PLAT432

 This test raised an ALERT for short intermolecular contacts.   
 In general, intermolecular contact distances should be not much smaller than   
 the sum of the associated van der Waals Radii. More often than not, such   
 short contacts can be a warning sign for errors. All short contacts should 
 therefore be examined in some detail. Interesting exceptions are carbonyl- 
 carbonyl interactions that often feature short O...C contacts (see Allen   
 et al. (1998) B54, 320-329, short NO2 O...O interactions and BF4(-) to 
 (aromatic) carbon contacts.