Systematically exact corrections from multisite configurations on the electronic structure of disordered alloys*

The Korringa-Kohn-Rostoker coherent-potential approximation (KKR-CPA) is widely used to study electronic structure and energy of disordered alloys, but the single-site CPA is missing effects from the local environment, including short-range order. A cluster-based \emph{non-local} CPA (NLCPA) was proposed that recovers the translational-invariance of the medium from reciprocal-space coarse-graining used in the dynamical cluster approximation (DCA), where corrections are casual and systematic as the cluster size increases. We implemented a first-principles KKR-NLCPA/DCA and study the effect of local environment, including short-range order, on the electronic structure of fcc $CuAu$ and bcc $NiAl$.