Orbital-based charge self-consistent Blackman-Esterling-Berk coherent potential approximation approach to substitutional disorder within a pseudopotential framework

We report the development of an ab initio electronic structure method applicable to generic substitutionally disordered real materials. Acharge self-consistent orbital-based extension of the coherent potential approximation due to Blackman, Esterling, and Berk (BEB-CPA) is combined with the mixed-basis pseudopotential density functional theory approach. The general formalism in terms of a nonorthogonal basis set including subtleties of the pseudopotential framework is outlined. The BEB-CPA is validated on a binary tight-binding toy model against exact diagonalization of a randomly occupied cluster. Finally, the developed ab initio approach is benchmarked for a binary CuZn alloy, which confirms the robustness of the charge self-consistent procedure with respect to initial conditions.