Implementation of screened hybrid functionals based on the Yukawa potential within the LAPW basis set

TL;DR

This paper reports the implementation of Yukawa-screened hybrid functionals in the WIEN2k code with LAPW basis, improving the accuracy of electronic structure calculations for solids, especially for properties like electric-field gradients.

Contribution

The paper introduces a novel implementation of Yukawa-screened hybrid functionals within the LAPW framework in WIEN2k, enhancing the calculation of electronic properties of solids.

Findings

Hybrid functionals outperform LDA and GGA in accuracy.

Significant improvement in electric-field gradient calculations.

Successful application to transition-energy and structural properties.

Abstract

The implementation of screened hybrid functionals into the WIEN2k code, which is based on the LAPW basis set, is reported. The Hartree-Fock exchange energy and potential are screened by means of the Yukawa potential as proposed by Bylander and Kleinman [Phys. Rev. B 41, 7868 (1990)] for the calculation of the electronic structure of solids with the screened-exchange local density approximation. Details of the formalism, which is based on the method of Massidda, Posternak, and Baldereschi [Phys. Rev. B 48, 5058 (1993)] for the unscreened Hartree-Fock exchange are given. The results for the transition-energy and structural properties of several test cases are presented. Results of calculations of the Cu electric-field gradient in Cu2O are also presented, and it is shown that the hybrid functionals are much more accurate than the standard local-density or generalized gradient approximations.