Efficient Computation of the Long-Range Exact Exchange using an Extended Screening Function

Fuente: arXiv
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Autori principali: Kokott, Sebastian, Blum, Volker, Scheffler, Matthias
Natura: Preprint
Pubblicazione: 2025
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author Kokott, Sebastian
Blum, Volker
Scheffler, Matthias
author_facet Kokott, Sebastian
Blum, Volker
Scheffler, Matthias
contents We introduce a computationally efficient screening for the Coulomb potential that also allows calculating approximated long-range exact exchange contributions with an accuracy similar to an explicit full-range evaluation of the exact exchange. Starting from the screening function of the HSE functional, i.e., the complementary error function, as zeroth order, a first-order Taylor expansion in terms of the screening parameter ω is proposed as an approximation of the long-range Coulomb potential. The resulting extended screening function has a similar spatial extend as the complementary error function leading to a computational speed comparable to screened hybrid functionals such as HSE06, but with long-range exact exchange contributions included. The approach is tested and demonstrated for prototypical semiconductors and organic crystals using the PBE0 functional. Predicted energy band gaps, total energies, cohesive energies, and lattice energies from the first-order approximated PBE0 functional are close to those from the unmodified PBE0 functional, but are obtained at significantly reduced computational cost.
format Preprint
id arxiv_https___arxiv_org_abs_2505_02536
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Efficient Computation of the Long-Range Exact Exchange using an Extended Screening Function
Kokott, Sebastian
Blum, Volker
Scheffler, Matthias
Materials Science
Chemical Physics
We introduce a computationally efficient screening for the Coulomb potential that also allows calculating approximated long-range exact exchange contributions with an accuracy similar to an explicit full-range evaluation of the exact exchange. Starting from the screening function of the HSE functional, i.e., the complementary error function, as zeroth order, a first-order Taylor expansion in terms of the screening parameter ω is proposed as an approximation of the long-range Coulomb potential. The resulting extended screening function has a similar spatial extend as the complementary error function leading to a computational speed comparable to screened hybrid functionals such as HSE06, but with long-range exact exchange contributions included. The approach is tested and demonstrated for prototypical semiconductors and organic crystals using the PBE0 functional. Predicted energy band gaps, total energies, cohesive energies, and lattice energies from the first-order approximated PBE0 functional are close to those from the unmodified PBE0 functional, but are obtained at significantly reduced computational cost.
title Efficient Computation of the Long-Range Exact Exchange using an Extended Screening Function
topic Materials Science
Chemical Physics
url https://arxiv.org/abs/2505.02536