Excited states from range-separated density-functional perturbation theory

We explore the possibility of calculating electronic excited states by using perturbation theory along a range-separated adiabatic connection. Starting from the energies of a partially interacting Hamiltonian, a first-order correction is defined with two variants of perturbation theory: a straightfo...

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Main Authors: Rebolini, Elisa, Toulouse, Julien, Teale, Andrew M., Helgaker, Trygve, Savin, Andreas
Format: Article
Published: Taylor and Francis 2015
Online Access:https://eprints.nottingham.ac.uk/31094/
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author Rebolini, Elisa
Toulouse, Julien
Teale, Andrew M.
Helgaker, Trygve
Savin, Andreas
author_facet Rebolini, Elisa
Toulouse, Julien
Teale, Andrew M.
Helgaker, Trygve
Savin, Andreas
author_sort Rebolini, Elisa
building Nottingham Research Data Repository
collection Online Access
description We explore the possibility of calculating electronic excited states by using perturbation theory along a range-separated adiabatic connection. Starting from the energies of a partially interacting Hamiltonian, a first-order correction is defined with two variants of perturbation theory: a straightforward perturbation theory, and an extension of the Görling-Levy one that has the advantage of keeping the ground-state density constant at each order in the perturbation. Only the first, simpler, variant is tested here on the helium and beryllium atoms and on the hydrogen molecule. The first-order correction within this perturbation theory improves significantly the total ground- and excited-state energies of the different systems. However, the excitation energies mostly deteriorate with respect to the zeroth-order ones, which may be explained by the fact that the ionization energy is no longer correct for all interaction strengths. The second (Görling-Levy) variant of the perturbation theory should improve these results but has not been tested yet along the range-separated adiabatic connection.
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spelling nottingham-310942020-05-04T17:02:34Z https://eprints.nottingham.ac.uk/31094/ Excited states from range-separated density-functional perturbation theory Rebolini, Elisa Toulouse, Julien Teale, Andrew M. Helgaker, Trygve Savin, Andreas We explore the possibility of calculating electronic excited states by using perturbation theory along a range-separated adiabatic connection. Starting from the energies of a partially interacting Hamiltonian, a first-order correction is defined with two variants of perturbation theory: a straightforward perturbation theory, and an extension of the Görling-Levy one that has the advantage of keeping the ground-state density constant at each order in the perturbation. Only the first, simpler, variant is tested here on the helium and beryllium atoms and on the hydrogen molecule. The first-order correction within this perturbation theory improves significantly the total ground- and excited-state energies of the different systems. However, the excitation energies mostly deteriorate with respect to the zeroth-order ones, which may be explained by the fact that the ionization energy is no longer correct for all interaction strengths. The second (Görling-Levy) variant of the perturbation theory should improve these results but has not been tested yet along the range-separated adiabatic connection. Taylor and Francis 2015-02-18 Article PeerReviewed Rebolini, Elisa, Toulouse, Julien, Teale, Andrew M., Helgaker, Trygve and Savin, Andreas (2015) Excited states from range-separated density-functional perturbation theory. Molecular Physics, 113 (13-14). pp. 1740-1749. ISSN 0026-8976 http://www.tandfonline.com/doi/full/10.1080/00268976.2015.1011248 doi:10.1080/00268976.2015.1011248 doi:10.1080/00268976.2015.1011248
spellingShingle Rebolini, Elisa
Toulouse, Julien
Teale, Andrew M.
Helgaker, Trygve
Savin, Andreas
Excited states from range-separated density-functional perturbation theory
title Excited states from range-separated density-functional perturbation theory
title_full Excited states from range-separated density-functional perturbation theory
title_fullStr Excited states from range-separated density-functional perturbation theory
title_full_unstemmed Excited states from range-separated density-functional perturbation theory
title_short Excited states from range-separated density-functional perturbation theory
title_sort excited states from range-separated density-functional perturbation theory
url https://eprints.nottingham.ac.uk/31094/
https://eprints.nottingham.ac.uk/31094/
https://eprints.nottingham.ac.uk/31094/