Volume 224, 2020

Weight dependence of local exchange–correlation functionals in ensemble density-functional theory: double excitations in two-electron systems

Abstract

Gross–Oliveira–Kohn (GOK) ensemble density-functional theory (GOK-DFT) is a time-independent extension of density-functional theory (DFT) which allows the computation of excited-state energies via the derivatives of the ensemble energy with respect to the ensemble weights. Contrary to the time-dependent version of DFT (TD-DFT), double excitations can be easily computed within GOK-DFT. However, to take full advantage of this formalism, one must have access to a weight-dependent exchange–correlation functional in order to model the infamous ensemble derivative contribution to the excitation energies. In the present article, we discuss the construction of first-rung (i.e., local) weight-dependent exchange–correlation density-functional approximations for two-electron atomic and molecular systems (He and H2) specifically designed for the computation of double excitations within GOK-DFT. In the spirit of optimally-tuned range-separated hybrid functionals, a two-step system-dependent procedure is proposed to obtain accurate energies associated with double excitations.

Graphical abstract: Weight dependence of local exchange–correlation functionals in ensemble density-functional theory: double excitations in two-electron systems

Associated articles

Article information

Article type
Paper
Submitted
13 may 2020
Accepted
15 iyn 2020
First published
15 iyn 2020

Faraday Discuss., 2020,224, 402-423

Weight dependence of local exchange–correlation functionals in ensemble density-functional theory: double excitations in two-electron systems

C. Marut, B. Senjean, E. Fromager and P. Loos, Faraday Discuss., 2020, 224, 402 DOI: 10.1039/D0FD00059K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements