COHERENT-POTENTIAL AND AVERAGE T-MATRIX APPROXIMATIONS FOR DISORDERED MUFFIN-TIN ALLOYS .2. APPLICATION TO REALISTIC SYSTEMS

In an earlier article, the electronic spectrum of the disordered alloy AxB1-x, using the coherent-potential (CPA) and the average t-matrix (ATA) approximations, was discussed within the framework of the muffintin Hamiltonian. Using the illustrative examples of CuxNi1-x and CuxZn1-x, the present paper exposes the physically relevant aspects of the electronic spectra of disordered transition and noble-metal alloys. Bloch spectral densities, complex energy bands, impurity levels, and average total and component densities of states are considered. We also discuss how the effects of transfer of charge between the constituents on their atomic potentials can be included in a semiempirical manner in the present framework. © 1979 The American Physical Society.