Systematics of fluorite-related structures. II. Structural diversity

The principles of systematics proposed in the previous paper are applied to the crystal structures with deficient fluorite-related frameworks. These frameworks are classified into ones with face-sharing fluorite modules and ones with quarter-of-face-sharing fluorite modules. It is shown that frameworks with face-sharing modules may be described using the concept of supermodule i.e. set of modules from which the whole framework may be obtained by its periodic repetition. Example compounds are considered.