Self-consistent cluster coherent-potential approximation for the tight-binding linearized-muffin-tin-orbitals approach to random binary alloys

Abstract
We have used the augmented-space formalism (ASF) to discuss the configuration averaging of random observables that one encounters in random systems, viz. the one-electron Green function or other related properties. The Hamiltonian of the constituents is obtained within the first-principles tight-binding linearized-muffin-tin-orbitals scheme. A self-consistent approach for the cluster coherent-potential function has been developed for substitutional binary alloys. Configuration averaging for the single-site coherent-potential approximation (CPA) and its cluster generalization (CCPA) is discussed using the ASF.