Distribution of Cations in Spinels

The concept of octahedral site preference energy in spinels has been extended to include Madelung and short-ranged as well as crystal field terms. A set of site preference energies is formulated which can be used to predict the ionic distribution of spinels involving the nontransition as well as the transition ions. The agreement between predicted and experimentally determined ionic distributions is surprisingly good, and a number of heretofore puzzling distributions are explained.