A new method of site occupancy analysis in substitutional mixed crystals by means of X‐ray crystal structure analysis (I). Pseudo lattice and superposition structure of a substitutional mixed crystal

Abstract

AbstractIn Part I the nature of disorder in mixed crystal structures will be discussed on the basis of a pseudo lattice concept. A mixed crystal pseudo lattice applicable to all atomic positions of these mixed crystal structures will be defined, and the concept of a statistically globaldisordered ideal structure will be introduced. The structure factor for mixed crystal structures will be derived in consideration of the statistic disorder of position and sort of the atoms. The interpretation of the mixed crystal structure as a superposition structure requires the replacement of Vegard's rule by a new one having a wider range of validity.