Variational energy functionals of the Green function and of the density tested on molecules
(2006) In Physical Review A (Atomic, Molecular and Optical Physics) 73(1).- Abstract
- We have calculated total energies of atoms and diatomic molecules from the Luttinger-Ward functional, using self-energy approximations to second order as well as the GW approximation. In order to assess the variational quality of this functional, we have also solved the Dyson equation self-consistently. The Luttinger-Ward functional is compared to the variational functional due to Klein, and we demonstrate that the variational property of the latter functional is inferior to that of the Luttinger-Ward functional. We also show how to obtain variational density functionals from the functionals of the Green function. These orbital functional schemes are important for systems where density-functional theory using local functionals of the... (More)
- We have calculated total energies of atoms and diatomic molecules from the Luttinger-Ward functional, using self-energy approximations to second order as well as the GW approximation. In order to assess the variational quality of this functional, we have also solved the Dyson equation self-consistently. The Luttinger-Ward functional is compared to the variational functional due to Klein, and we demonstrate that the variational property of the latter functional is inferior to that of the Luttinger-Ward functional. We also show how to obtain variational density functionals from the functionals of the Green function. These orbital functional schemes are important for systems where density-functional theory using local functionals of the density necessarily fails. We derive an optimized effective potential (OEP) scheme that is based on the Luttinger-Ward functional and, unlike the conventional OEP schemes, produces energies in good agreement with the values obtained from the self-consistent Green function. Our calculations show that, when applied to molecules, the Luttinger-Ward functional is more sensitive to the quality of the input Green function than when applied to atoms, but the energies are remarkably close to the self-consistent values when the Hartree-Fock Green function is used as input. This Luttinger-Ward functional is therefore a simple and efficient method for studying the merits of various self-energy approximations while avoiding the computationally demanding task of solving the Dyson equation self-consistently. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/417674
- author
- Dahlen, Nils-Erik LU ; van Leeuwen, R and von Barth, Ulf LU
- organization
- publishing date
- 2006
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physical Review A (Atomic, Molecular and Optical Physics)
- volume
- 73
- issue
- 1
- publisher
- American Physical Society
- external identifiers
-
- wos:000235008900085
- scopus:33144466655
- ISSN
- 1050-2947
- DOI
- 10.1103/PhysRevA.73.012511
- language
- English
- LU publication?
- yes
- id
- 9f274c6c-e6e8-4508-a8c4-ca11993b42bd (old id 417674)
- date added to LUP
- 2016-04-01 12:32:13
- date last changed
- 2022-04-13 20:22:26
@article{9f274c6c-e6e8-4508-a8c4-ca11993b42bd,
abstract = {{We have calculated total energies of atoms and diatomic molecules from the Luttinger-Ward functional, using self-energy approximations to second order as well as the GW approximation. In order to assess the variational quality of this functional, we have also solved the Dyson equation self-consistently. The Luttinger-Ward functional is compared to the variational functional due to Klein, and we demonstrate that the variational property of the latter functional is inferior to that of the Luttinger-Ward functional. We also show how to obtain variational density functionals from the functionals of the Green function. These orbital functional schemes are important for systems where density-functional theory using local functionals of the density necessarily fails. We derive an optimized effective potential (OEP) scheme that is based on the Luttinger-Ward functional and, unlike the conventional OEP schemes, produces energies in good agreement with the values obtained from the self-consistent Green function. Our calculations show that, when applied to molecules, the Luttinger-Ward functional is more sensitive to the quality of the input Green function than when applied to atoms, but the energies are remarkably close to the self-consistent values when the Hartree-Fock Green function is used as input. This Luttinger-Ward functional is therefore a simple and efficient method for studying the merits of various self-energy approximations while avoiding the computationally demanding task of solving the Dyson equation self-consistently.}},
author = {{Dahlen, Nils-Erik and van Leeuwen, R and von Barth, Ulf}},
issn = {{1050-2947}},
language = {{eng}},
number = {{1}},
publisher = {{American Physical Society}},
series = {{Physical Review A (Atomic, Molecular and Optical Physics)}},
title = {{Variational energy functionals of the Green function and of the density tested on molecules}},
url = {{http://dx.doi.org/10.1103/PhysRevA.73.012511}},
doi = {{10.1103/PhysRevA.73.012511}},
volume = {{73}},
year = {{2006}},
}