Advanced

Towards nonlocal density functionals by explicit modeling of the exchange-correlation hole in inhomogeneous systems

Giesbertz, K. J. H. ; van Leeuwen, R. and von Barth, Ulf LU (2013) In Physical Review A (Atomic, Molecular and Optical Physics) 87(2).
Abstract
We put forward an approach for the development of a nonlocal density functional by a direct modeling of the shape of exchange-correlation (xc) hole in inhomogeneous systems. The functional is aimed at giving an accurate xc energy and an accurate corresponding xc potential even in difficult near-degeneracy situations such as molecular bond breaking. In particular we demand that: (1) the xc hole properly contains -1 electron, (2) the xc potential has the asymptotic -1/r behavior outside finite systems, and (3) the xc potential has the correct step structure related to the derivative discontinuities of the xc energy functional. None of the currently existing functionals satisfies all these requirements. These demands are achieved by screening... (More)
We put forward an approach for the development of a nonlocal density functional by a direct modeling of the shape of exchange-correlation (xc) hole in inhomogeneous systems. The functional is aimed at giving an accurate xc energy and an accurate corresponding xc potential even in difficult near-degeneracy situations such as molecular bond breaking. In particular we demand that: (1) the xc hole properly contains -1 electron, (2) the xc potential has the asymptotic -1/r behavior outside finite systems, and (3) the xc potential has the correct step structure related to the derivative discontinuities of the xc energy functional. None of the currently existing functionals satisfies all these requirements. These demands are achieved by screening the exchange hole in such a way that the pair-correlation function is symmetric and satisfies the sum rule. These two features immediately imply (1) and (2) while the explicit dependence of the exchange hole on the Kohn-Sham orbitals implies (3). Preliminary calculations show an improved physical description of the dissociating hydrogen molecule. Though the total energy is still far from perfect, the binding curve from our nonlocal density functional provides a significant improvement over the local density approximation. DOI: 10.1103/PhysRevA.87.022514 (Less)
Please use this url to cite or link to this publication:
author
; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review A (Atomic, Molecular and Optical Physics)
volume
87
issue
2
article number
022514
publisher
American Physical Society
external identifiers
  • wos:000315479700010
  • scopus:84874526997
ISSN
1050-2947
DOI
10.1103/PhysRevA.87.022514
language
English
LU publication?
yes
id
f7f8ecce-d3d9-4dae-a968-bf88ece67e3d (old id 3670229)
date added to LUP
2016-04-01 09:52:27
date last changed
2020-01-15 01:03:35
@article{f7f8ecce-d3d9-4dae-a968-bf88ece67e3d,
  abstract     = {We put forward an approach for the development of a nonlocal density functional by a direct modeling of the shape of exchange-correlation (xc) hole in inhomogeneous systems. The functional is aimed at giving an accurate xc energy and an accurate corresponding xc potential even in difficult near-degeneracy situations such as molecular bond breaking. In particular we demand that: (1) the xc hole properly contains -1 electron, (2) the xc potential has the asymptotic -1/r behavior outside finite systems, and (3) the xc potential has the correct step structure related to the derivative discontinuities of the xc energy functional. None of the currently existing functionals satisfies all these requirements. These demands are achieved by screening the exchange hole in such a way that the pair-correlation function is symmetric and satisfies the sum rule. These two features immediately imply (1) and (2) while the explicit dependence of the exchange hole on the Kohn-Sham orbitals implies (3). Preliminary calculations show an improved physical description of the dissociating hydrogen molecule. Though the total energy is still far from perfect, the binding curve from our nonlocal density functional provides a significant improvement over the local density approximation. DOI: 10.1103/PhysRevA.87.022514},
  author       = {Giesbertz, K. J. H. and van Leeuwen, R. and von Barth, Ulf},
  issn         = {1050-2947},
  language     = {eng},
  number       = {2},
  publisher    = {American Physical Society},
  series       = {Physical Review A (Atomic, Molecular and Optical Physics)},
  title        = {Towards nonlocal density functionals by explicit modeling of the exchange-correlation hole in inhomogeneous systems},
  url          = {http://dx.doi.org/10.1103/PhysRevA.87.022514},
  doi          = {10.1103/PhysRevA.87.022514},
  volume       = {87},
  year         = {2013},
}