Excitation energies from Görling–Levy perturbation theory along the range-separated adiabatic connection

Rebolini, Elisa; Teale, Andrew M.; Helgaker, Trygve; Savin, Andreas; Toulouse, Julien

Abstract

A Görling–Levy (GL)-based perturbation theory along the range-separated adiabatic connection is assessed for the calculation of electronic excitation energies. In comparison with the Rayleigh–Schrödinger (RS)-based perturbation theory this GL-based perturbation theory keeps the ground-state density constant at each order and thus gives the correct ionisation energy at each order. Excitation energies up to first order in the perturbation have been calculated numerically for the helium and beryllium atoms and the hydrogen molecule without introducing any density-functional approximations. In comparison with the RS-based perturbation theory, the present GL-based perturbation theory gives much more accurate excitation energies for Rydberg states but similar excitation energies for valence states.

Citation

Rebolini, E., Teale, A. M., Helgaker, T., Savin, A., & Toulouse, J. (2018). Excitation energies from Görling–Levy perturbation theory along the range-separated adiabatic connection. Molecular Physics, 116(11), 1443-1451. https://doi.org/10.1080/00268976.2017.1422811

• Journal Article Type: Article
• Acceptance Date: Dec 22, 2017
• Online Publication Date: Jan 15, 2018
• Publication Date: Jun 15, 2018
• Deposit Date: Mar 28, 2018
• Publicly Available Date: Jan 16, 2019
• Journal: Molecular Physics
• Print ISSN: 0026-8976
• Electronic ISSN: 1362-3028
• Publisher: Taylor and Francis
• Peer Reviewed: Peer Reviewed
• Volume: 116
• Issue: 11
• Pages: 1443-1451
• DOI: https://doi.org/10.1080/00268976.2017.1422811
• Keywords: Density-functional theory, range separation, adiabatic connection, perturbation theory, excitation energies
• Public URL: https://nottingham-repository.worktribe.com/output/938714
• Publisher URL: https://www.tandfonline.com/doi/full/10.1080/00268976.2017.1422811
• Additional Information: This is an Accepted Manuscript of an article published by Taylor & Francis in Molecular Physics on 15 January 2018, available online: http://www.tandfonline.com/10.1080/00268976.2017.1422811.
• Contract Date: Mar 28, 2018