OD approach to polytypism: examples, problems, indications

Abstract

Abstract The relationships between polytypism and OD structures are discussed, with presentation of some examples in different classes of compounds: polymorphism and polytypism in 9,10 phenantrenequinone; OD structures in latiumite and tuscanite family; polytypism in kaolinite family. The basic elements of OD theory are given, both for structures consisting of OD layers all of the same kind and for structures consisting of two or more distinct kinds of OD layers, and the advantages of an OD approach to polytypism, together with its limitations, are presented and discussed.