Multiple-scattering theory of binary alloys in single-site approximation

Abstract

The application of the single-site approximation to investigate electronic properties of substitutional binary alloys is discussed within the framework of the muffin-tin model. On the basis of the multiple-scattering theory, new expressions for the complete and restricted averages of the site diagonal elements of the alloy scattering matrix are presented. These expressions are given in terms of an arbitrary crystalline reference medium and can be used in conjunction with either the coherent potential (CPA) or the average t-matrix (ATA) approximations. It is also shown that the previous expressions for the restricted averages of the alloy scattering matrix can only be used in conjunction with the CPA. The expressions in this paper reduce to the CPA results for a suitable choice of the reference medium.