A software tool for the topological and geometrical characterization of three-dimensional frameworks

The software tool ‘zeoTsites’ is described and its ability to characterize the topology of three-dimensional nets is analysed based on covalent oxides where knot atoms are of tetrahedral or higher coordination. For these systems, the coordination sequences and vertex symbols are calculated by the program. Based on the connectivity of the solid, bond distances and angles are calculated and averaged over each different crystallographic and topologic knot atom in the framework. Two case studies are presented, firstly for wadeite type minerals, and secondly for the zeolites nabesite and weinebeneite that contain the rather unusual spiro-5 unit formed from two interconnected three-membered rings.