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

TL;DR

This paper introduces a Wannier-based CPA method for efficient simulation of random alloys, validated on Fe-based alloys, matching traditional methods and enabling broader applications.

Contribution

A novel Wannier-based CPA formulation that is computationally efficient and code-independent, suitable for large systems and diverse physical quantities.

Findings

Wannier-CPA results closely match KKR-CPA results.

The method is computationally efficient for large systems.

Validated on Fe-X alloys with consistent magnetic and electronic properties.

Abstract

We develop a formulation of the coherent potential approximation (CPA) on the basis of the Wannier representation to develop a computationally efficient method for the treatment of homogeneous random alloys that is independent on the applied first-principles electric structure code. To verify the performance of this CPA implementation within the Wannier representation, we examine the Bloch spectral function, the density of states (DOS), 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 KKR Green's function method. The Wannier-CPA and the KKR-CPA lead to results very close to each other. The presented Wannier-CPA method has a wide potential applicability to other physical quantities and large compound systems because of its low computational effort required.