COULOMB ENERGIES IN DISORDERED ALLOYS AND IMPROVEMENTS ON THE COHERENT-POTENTIAL APPROXIMATION

Order-N calculations of the electronic states of models of random subs titutional Cu-Zn alloys have been carried out. By analyzing the result s, new general features that are characteristic of the Coulomb energie s of alloys have been discovered. This article shows how they compare with other models of alloys that have been discussed in the literature . The most important consequence of these calculations is the new insi ght that they give into the nature of the Coulomb energy in the densit y functional theory.