checkCIF procedure

PLAT605

 Crystal structures in general do not contain large solvent accessible voids
 in the lattice. Most structures lose their long-range ordering when solvent
 molecules leave the crystal. Only when the remaining network is strongly   
 bonded (e.g. zeolites and some hydrogen bonded networks) the crystal   
 structure may survive. 
 Residual voids in a structure may indicate the omission of (disordered)
 density from the model. Disordered density may go undetected when smeared  
 since peak search programs are not designed to locate maxima on density
 ridges. The presence or absence of residual density in the void may be 
 verified on a printed/plotted difference Fourier map or with PLATON/SQUEEZE.   
 Voids of 40 Ang**3 may accommodate H2O. Small molecules such as
 Tetrahydrofuran have typical volumes in the 100 to 200 Ang**3 range.   
 This test reports the volume of the largest solvent accessible void in the 
 structure. 
 A paper reporting a crystal structure with a significant solvent accessible
 void should at the least discuss the issue.
 NOTE: The use of PLATON/SQUEEZE was reported in the CIF.