The coupling constant averaged exchange–correlation energy density

Irons, Tom J.P.; Teale, Andrew M.

Abstract

The exchange–correlation energy, central to density-functional theory, may be represented in terms of the coupling constant averaged (CCA) exchange–correlation energy density. We present an approach to calculate the CCA energy density using accurate ab initio methods and its application to simple atomic systems. This function provides a link between intrinsically non-local, many-body electronic structure methods and simple local and semi-local density-functional approximations (DFAs). The CCA energy density is resolved into separate exchange and correlation terms and the features of each compared with those of quantities commonly used to construct DFAs. In particular, the more complex structure of the correlation energy density is found to exhibit features that align well with those present in the Laplacian of the density, suggesting its role as a key variable to be used in the construction of improved semi-local correlation functionals. The accurate results presented in this work are also compared with those provided by the Laplacian-dependent Becke–Roussel model for the exchange energy.

Citation

Irons, T. J., & Teale, A. M. (2016). The coupling constant averaged exchange–correlation energy density. Molecular Physics, 114(3-4), 1-14. https://doi.org/10.1080/00268976.2015.1096424

• Journal Article Type: Article
• Acceptance Date: Sep 14, 2015
• Online Publication Date: Oct 27, 2015
• Publication Date: Feb 1, 2016
• Deposit Date: Dec 16, 2015
• Publicly Available Date: Dec 16, 2015
• Journal: Molecular Physics
• Print ISSN: 0026-8976
• Electronic ISSN: 1362-3028
• Publisher: Taylor and Francis
• Peer Reviewed: Peer Reviewed
• Volume: 114
• Issue: 3-4
• Pages: 1-14
• DOI: https://doi.org/10.1080/00268976.2015.1096424
• Keywords: energy densities, density-functional theory, exchange-correlation, adiabatic connection, coupled-cluster thoery
• Public URL: https://nottingham-repository.worktribe.com/output/770756
• Publisher URL: http://www.tandfonline.com/doi/full/10.1080/00268976.2015.1096424
• Additional Information: Peer Review Statement: The publishing and review policy for this title is described in its Aims & Scope.; Aim & Scope: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=tmph20