ELECTRONIC-STRUCTURE OF METALLIC ALLOYS USING CHARGE-NEUTRAL ATOMIC SPHERES

Based on the idea of charge-neutral atomic spheres we have calculated the electronic structure of ordered and disordered Cu-Zn, Ni-Pt, and A l-Li alloys using the linear-muffin-tin-orbital (LMTO) method and the Korringa-Kohn-Rostoker coherent potential approximation (KKR CPA) meth od in the atomic-sphere approximation (ASA), respectively. The equilib rium lattice constants and the formation energies of ordered alloys ob tained with the LMTO-ASA method show that the calculations done with c harge-neutral atomic spheres are closer to the experimental results th an the conventional equivolume atomic-sphere-type calculations. In the case of disordered alloys, we find that charge-neutral atomic spheres are essential for the stability of these alloys within the KKR-ASA CP A method where the Madelung-type contribution is neglected. Our result s clearly indicate that for disordered alloys any future implementatio n of a full-potential method within the single-site CPA should be carr ied out with charge-neutral cells rather than the Wigner-Seitz cells.