This represents a continuation of research previously supported by NSF grant EAR84-08164, concerning fundamental studies of the structures, bonding, and crystal chemistry of complex minerals. The project involves the systematic study of spatial (both geometrical and topological) and chemical relationships among crystal structures. When structures are considered as connected arrays of fundamental structural units and ordered vacancies are taken into account, many complex oxysalt structures are found to be analogous to simple intermetallic compounds. The objective of this project is to examine these relationships systematically in order to determine general relations among mineral structure types. The results of these studies will contribute to our understanding of the nature of structural organization and bonding in solids.
