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Comparison of overlap-based models for approximating the exchange-repulsion energy

Söderhjelm, Pär LU ; Karlström, Gunnar LU and Ryde, Ulf LU orcid (2006) In Journal of Chemical Physics 124(24).
Abstract
Different ways of approximating the exchange-repulsion energy with a classical potential function have been investigated by fitting various expressions to the exact exchange-repulsion energy for a large set of molecular dimers. The expressions involve either the orbital overlap or the electron-density overlap. For comparison, the parameter-free exchange-repulsion model of the effective fragment potential (EFP) is also evaluated. The results show that exchange-repulsion energy is nearly proportional to both the orbital overlap and the density overlap. For accurate results, a distance-dependent correction is needed in both cases. If few parameters are desired, orbital overlap is superior to density overlap, but the fit to density overlap can... (More)
Different ways of approximating the exchange-repulsion energy with a classical potential function have been investigated by fitting various expressions to the exact exchange-repulsion energy for a large set of molecular dimers. The expressions involve either the orbital overlap or the electron-density overlap. For comparison, the parameter-free exchange-repulsion model of the effective fragment potential (EFP) is also evaluated. The results show that exchange-repulsion energy is nearly proportional to both the orbital overlap and the density overlap. For accurate results, a distance-dependent correction is needed in both cases. If few parameters are desired, orbital overlap is superior to density overlap, but the fit to density overlap can be significantly improved by introducing more parameters. The EFP performs well, except for delocalized pi systems. However, an overlap expression with a few parameters seems to be slightly more accurate and considerably easier to approximate. (c) 2006 American Institute of Physics. (Less)
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; and
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publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Chemical Physics
volume
124
issue
24
article number
244101
publisher
American Institute of Physics (AIP)
external identifiers
  • wos:000238730600007
  • scopus:33745699625
ISSN
0021-9606
DOI
10.1063/1.2206182
language
English
LU publication?
yes
additional info
The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Theoretical Chemistry (S) (011001039)
id
1d78bf28-4e7f-4f21-87d1-993aad3fa102 (old id 404519)
date added to LUP
2016-04-01 11:54:26
date last changed
2020-11-22 03:02:29
@article{1d78bf28-4e7f-4f21-87d1-993aad3fa102,
  abstract     = {Different ways of approximating the exchange-repulsion energy with a classical potential function have been investigated by fitting various expressions to the exact exchange-repulsion energy for a large set of molecular dimers. The expressions involve either the orbital overlap or the electron-density overlap. For comparison, the parameter-free exchange-repulsion model of the effective fragment potential (EFP) is also evaluated. The results show that exchange-repulsion energy is nearly proportional to both the orbital overlap and the density overlap. For accurate results, a distance-dependent correction is needed in both cases. If few parameters are desired, orbital overlap is superior to density overlap, but the fit to density overlap can be significantly improved by introducing more parameters. The EFP performs well, except for delocalized pi systems. However, an overlap expression with a few parameters seems to be slightly more accurate and considerably easier to approximate. (c) 2006 American Institute of Physics.},
  author       = {Söderhjelm, Pär and Karlström, Gunnar and Ryde, Ulf},
  issn         = {0021-9606},
  language     = {eng},
  number       = {24},
  publisher    = {American Institute of Physics (AIP)},
  series       = {Journal of Chemical Physics},
  title        = {Comparison of overlap-based models for approximating the exchange-repulsion energy},
  url          = {http://dx.doi.org/10.1063/1.2206182},
  doi          = {10.1063/1.2206182},
  volume       = {124},
  year         = {2006},
}