The coupling constant averaged exchange–correlation energy density

Irons, Tom J.P. and Teale, Andrew M. (2016) The coupling constant averaged exchange–correlation energy density. Molecular Physics, 114 (3-4). pp. 484-497. ISSN 1362-3028

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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.

Item Type: Article
Additional Information: This is an Accepted Manuscript of an article published by Taylor & Francis in Molecular Physics on 27 October 2015, available online: http://wwww.tandfonline.com/10.1080/00268976.2015.1096424
Keywords: energy densities, density-functional theory, exchange-correlation, adiabatic connection, coupled-cluster thoery
Schools/Departments: University of Nottingham UK Campus > Faculty of Science > School of Chemistry
Identification Number: https://doi.org/10.1080/00268976.2015.1096424
Depositing User: Teale, Andrew
Date Deposited: 16 Dec 2015 11:43
Last Modified: 16 Sep 2016 00:10
URI: http://eprints.nottingham.ac.uk/id/eprint/31088

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