First-Principles Wannier Functions of Silicon and Gallium Arsenide

TL;DR

This paper develops a self-consistent real-space method within density functional theory to calculate Wannier functions for silicon and gallium arsenide, enabling accurate predictions of their electronic and structural properties.

Contribution

It introduces a novel self-consistent approach to compute Wannier functions directly from DFT, improving the accuracy of related property calculations.

Findings

Accurate total energy, lattice constant, and phonon frequency calculations.

Effective charges of GaAs agree with linear response results.

Method applicable to other semiconductors for property prediction.

Abstract

We present a self-consistent, real-space calculation of the Wannier functions of Si and GaAs within density functional theory. We minimize the total energy functional with respect to orbitals which behave as Wannier functions under crystal translations and, at the minimum, are orthogonal. The Wannier functions are used to calculate the total energy, lattice constant, bulk modulus, and the frequency of the zone-center TO phonon of the two semiconductors with the accuracy required nowadays in ab-initio calculations. Furthermore, the centers of the Wannier functions are used to compute the macroscopic polarization of Si and GaAs in zero electric field. The effective charges of GaAs, obtained by finite differentiation of the polarization, agree with the results of linear response theory.