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Improved local-field corrections to the G_ {0} W approximation in jellium: Importance of consistency relations

Almbladh, Carl-Olof LU and Hindgren, Mikael (1997) In Physical Review B 56(20). p.12832-12839
Abstract
We study the effects of local vertex corrections to the self-energy of the electron gas. We find that a vertex derived from time-dependent density-functional theory can give accurate self-energies, provided, however, a proper decay at large momentum transfer (large q) is built into the vertex function. (The local-density approximation for the vertex fails badly.) Total energies are calculated from the Galitskii-Migdal formula, and it is shown that a proper large-q behavior results in a close consistency between the chemical potentials derived from these energies and those obtained directly from the self-energy. We show that this internal consistency depends critically on including the same vertex correction in both the self-energy and the... (More)
We study the effects of local vertex corrections to the self-energy of the electron gas. We find that a vertex derived from time-dependent density-functional theory can give accurate self-energies, provided, however, a proper decay at large momentum transfer (large q) is built into the vertex function. (The local-density approximation for the vertex fails badly.) Total energies are calculated from the Galitskii-Migdal formula, and it is shown that a proper large-q behavior results in a close consistency between the chemical potentials derived from these energies and those obtained directly from the self-energy. We show that this internal consistency depends critically on including the same vertex correction in both the self-energy and the screening function. In addition the total energies become almost as accurate as those from elaborate Monte Carlo calculations. This as well as previous works show that self-energy corrections are important for properly describing electron propagation at energies around and above the plasmon energy. For easy use in calculations of photoemission and x-ray extended fine structure spectra, we parametrize our calculated self-energies in terms of a simple analytical expression. (Less)
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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review B
volume
56
issue
20
pages
12832 - 12839
publisher
American Physical Society
external identifiers
  • scopus:0006846587
ISSN
1550-235X
language
English
LU publication?
yes
id
bf22f475-bf47-4d5a-b007-506bb15c9593 (old id 8774182)
date added to LUP
2016-04-04 13:48:22
date last changed
2022-01-30 00:56:34
@article{bf22f475-bf47-4d5a-b007-506bb15c9593,
  abstract     = {{We study the effects of local vertex corrections to the self-energy of the electron gas. We find that a vertex derived from time-dependent density-functional theory can give accurate self-energies, provided, however, a proper decay at large momentum transfer (large q) is built into the vertex function. (The local-density approximation for the vertex fails badly.) Total energies are calculated from the Galitskii-Migdal formula, and it is shown that a proper large-q behavior results in a close consistency between the chemical potentials derived from these energies and those obtained directly from the self-energy. We show that this internal consistency depends critically on including the same vertex correction in both the self-energy and the screening function. In addition the total energies become almost as accurate as those from elaborate Monte Carlo calculations. This as well as previous works show that self-energy corrections are important for properly describing electron propagation at energies around and above the plasmon energy. For easy use in calculations of photoemission and x-ray extended fine structure spectra, we parametrize our calculated self-energies in terms of a simple analytical expression.}},
  author       = {{Almbladh, Carl-Olof and Hindgren, Mikael}},
  issn         = {{1550-235X}},
  language     = {{eng}},
  number       = {{20}},
  pages        = {{12832--12839}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review B}},
  title        = {{Improved local-field corrections to the G_ {0} W approximation in jellium: Importance of consistency relations}},
  volume       = {{56}},
  year         = {{1997}},
}