Wave-function inspired density functional applied to the H2/H2 + challenge

Loading...
Thumbnail Image

Access rights

openAccess

URL

Journal Title

Journal ISSN

Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2016-07-01

Major/Subject

Mcode

Degree programme

Language

en

Pages

1-16

Series

New Journal of Physics, Volume 18, issue 7

Abstract

We start from the Bethe-Goldstone equation (BGE) to derive a simple orbital-dependent correlation functional - BGE2 - which terminates the BGE expansion at the second-order, but retains the self-consistent coupling of electron-pair correlations. We demonstrate that BGE2 is size consistent and one-electron 'self-correlation' free. The electron-pair correlation coupling ensures the correct H2 dissociation limit and gives a finite correlation energy for any system even if it has a no energy gap. BGE2 provides a good description of both H2 and dissociation, which is regarded as a great challenge in density functional theory (DFT). We illustrate the behavior of BGE2 analytically by considering H2 in a minimal basis. Our analysis shows that BGE2 captures essential features of the adiabatic connection path that current state-of-the-art DFT approximations do not.

Description

Keywords

adiabatic-connetion path, density-functional theory, molecular dissociation, near-degeneracy correlation

Other note

Citation

Zhang, I Y, Rinke, P & Scheffler, M 2016, ' Wave-function inspired density functional applied to the H 2 /H 2 + challenge ', New Journal of Physics, vol. 18, no. 7, 073026, pp. 1-16 . https://doi.org/10.1088/1367-2630/18/7/073026