Wannier-based implementation of the coherent potential approximation with applications to Fe-based transition metal alloys

We develop a formulation of the coherent potential approximation (CPA) on the basis of the Wannier representation to advance a computationally efficient method for the treatment of homogeneous random alloys that is independent of the applied first-principles electronic structure code. To verify the performance of this CPA implementation within the Wannier representation, we examine the Bloch spectral function, the density of states, and the magnetic moment in Fe-based transition metal alloys Fe-X (X=V, Co, Ni, and Cu) and compare the results with those of the well-established CPA implementation based on the Korringa-Kohn-Rostoker (KKR) Green's function method. The Wannier-CPA and the KKR-CPA methods lead to very similar results. The presented Wannier-CPA method has a wide potential applicability to other physical quantities and large compound systems because of the low computational effort required.