Non-perturbative embedding of local defects in crystalline materials

TL;DR

This paper introduces a variational model for accurately computing the electronic structure of crystalline materials with local defects, utilizing Wannier functions for efficient discretization within existing quantum frameworks.

Contribution

It proposes a novel non-perturbative variational approach that expands the defect-induced density matrix difference in Wannier basis, applicable to various electronic structure methods.

Findings

Effective discretization of defect states in crystals

Compatible with semi-empirical and DFT frameworks

Improves accuracy of defect modeling in materials

Abstract

We present a new variational model for computing the electronic first-order density matrix of a crystalline material in presence of a local defect. A natural way to obtain variational discretizations of this model is to expand the difference Q between the density matrix of the defective crystal and the density matrix of the perfect crystal, in a basis of precomputed maximally localized Wannier functions of the reference perfect crystal. This approach can be used within any semi-empirical or Density Functional Theory framework.