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Variational total energies from Phi and Psi derivable theories

Almbladh, Carl-Olof LU ; von Barth, Ulf LU and van Leeuwen, Robert (1999) In International Journal of Modern Physics B 13. p.535-540
Abstract
The old variational functional for the total energy

of a many-electron system proposed by Luttinger and Ward (LW) in 1960 is

here tested on the electron gas at the level of the GW approximation. Using

a simple non-interacting Green function to evaluate the fuctional we obtain

a correlation energy very close to that of a fully self-consistent $GW$

calculation which, in turn, is very close to that of an elaborate Monte-Carlo

calculation. Encouraged by this success we have gone beyond the LW theory

and constructed a new functional $Psi[G,W]$ having the Green's function $G$

and the screened interaction $W$ as two completely independent variables.

The electronic... (More)
The old variational functional for the total energy

of a many-electron system proposed by Luttinger and Ward (LW) in 1960 is

here tested on the electron gas at the level of the GW approximation. Using

a simple non-interacting Green function to evaluate the fuctional we obtain

a correlation energy very close to that of a fully self-consistent $GW$

calculation which, in turn, is very close to that of an elaborate Monte-Carlo

calculation. Encouraged by this success we have gone beyond the LW theory

and constructed a new functional $Psi[G,W]$ having the Green's function $G$

and the screened interaction $W$ as two completely independent variables.

The electronic self-energy $Sigma$ and the irreducible polarizability $P$

obtains from $Psi$ as functional derivatives with respect to $G$ and

$W$. The new $Psi$ functional allows for an even simpler way of obtaining

accurate correlation energies and, at the $GW$ level, alredy a non-interacting

$G$ and a simple plasmon-pole approximation to $W$ gives almost the same

correlation energy as before. (Less)
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organization
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type
Contribution to journal
publication status
published
subject
keywords
Manybody Theory, Electron correlation
in
International Journal of Modern Physics B
volume
13
pages
535 - 540
publisher
World Scientific
ISSN
0217-9792
language
English
LU publication?
yes
id
330c4653-02a5-4a3f-a9c2-dddc247450ae (old id 925540)
date added to LUP
2015-06-20 12:20:46
date last changed
2016-04-16 10:04:26
@misc{330c4653-02a5-4a3f-a9c2-dddc247450ae,
  abstract     = {The old variational functional for the total energy<br/><br>
of a many-electron system proposed by Luttinger and Ward (LW) in 1960 is<br/><br>
here tested on the electron gas at the level of the GW approximation. Using<br/><br>
a simple non-interacting Green function to evaluate the fuctional we obtain<br/><br>
a correlation energy very close to that of a fully self-consistent $GW$<br/><br>
calculation which, in turn, is very close to that of an elaborate Monte-Carlo<br/><br>
calculation. Encouraged by this success we have gone beyond the LW theory<br/><br>
and constructed a new functional $Psi[G,W]$ having the Green's function $G$<br/><br>
and the screened interaction $W$ as two completely independent variables.<br/><br>
The electronic self-energy $Sigma$ and the irreducible polarizability $P$<br/><br>
obtains from $Psi$ as functional derivatives with respect to $G$ and<br/><br>
$W$. The new $Psi$ functional allows for an even simpler way of obtaining<br/><br>
accurate correlation energies and, at the $GW$ level, alredy a non-interacting<br/><br>
$G$ and a simple plasmon-pole approximation to $W$ gives almost the same<br/><br>
correlation energy as before.},
  author       = {Almbladh, Carl-Olof and von Barth, Ulf and van Leeuwen, Robert},
  issn         = {0217-9792},
  keyword      = {Manybody Theory,Electron correlation},
  language     = {eng},
  pages        = {535--540},
  publisher    = {ARRAY(0xb417fb8)},
  series       = {International Journal of Modern Physics B},
  title        = {Variational total energies from Phi and Psi derivable theories},
  volume       = {13},
  year         = {1999},
}