SELF-CONSISTENT CLUSTER COHERENT-POTENTIAL APPROXIMATION FOR THE TIGHT-BINDING LINEARIZED-MUFFIN-TIN-ORBITALS APPROACH TO RANDOM BINARY-ALLOYS

We have used the augmented-space formalism (ASF) to discuss the config uration averaging of random observables that one encounters in random systems, viz. the one-electron Green function or other related propert ies. 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 b een developed for substitutional binary alloys. Configuration averagin g for the single-site coherent-potential approximation (CPA) and its c luster generalization (CCPA) is discussed using the ASF.