Excited states from range-separated density-functional perturbation theory

Rebolini, Elisa and Toulouse, Julien and Teale, Andrew M. and 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

[img]
Preview
PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Available under Licence Creative Commons Attribution.
Download (340kB) | Preview

Abstract

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.

Item Type: Article
Schools/Departments: University of Nottingham UK Campus > Faculty of Science > School of Chemistry
Identification Number: https://doi.org/10.1080/00268976.2015.1011248
Depositing User: Teale, Andrew
Date Deposited: 16 Dec 2015 13:35
Last Modified: 20 Sep 2016 15:32
URI: http://eprints.nottingham.ac.uk/id/eprint/31094

Actions (Archive Staff Only)

Edit View Edit View