Reproducibility in $G_0W_0$ Calculations for Solids
Abstract
Ab initio many-body perturbation theory within the approximation is a Green's function formalism widely used in the calculation of quasiparticle excitation energies of solids. In what has become an increasingly standard approach, Kohn-Sham eigenenergies, generated from a DFT calculation with a strategically-chosen exchange correlation functional ``starting point'', are used to construct and , and then perturbatively corrected by the resultant self-energy. In practice, there are several ways to construct the self-energy, and these can lead to variations in predicted quasiparticle energies. For example, for ZnO and TiO, reported fundamental gaps can vary by more than 1 eV. In this work, we address the convergence and key approximations in contemporary calculations, including frequency-integration schemes and the treatment of the Coulomb divergence in the exact-exchange term. We study several systems,and compare three different codes: BerkeleyGW, Abinit and Yambo. We demonstrate, for the first time, that the same quasiparticle energies for systems in the condensed phase can be obtained with different codes, and we provide a comprehensive assessment of implementations of the approximation.
Keywords
Cite
@article{arxiv.1903.06865,
title = {Reproducibility in $G_0W_0$ Calculations for Solids},
author = {Tonatiuh Rangel and Mauro Del Ben and Daniele Varsano and Gabriel Antonius and Fabien Bruneval and Felipe H. da Jornada and Michiel J. van Setten and Okan K. Orhan and David D. O'Regan and Andrew Canning and Andrea Ferretti and Andrea Marini and Gian-Marco Rignanese and Jack Deslippe and Steven G. Louie and Jeffrey B. Neaton},
journal= {arXiv preprint arXiv:1903.06865},
year = {2023}
}