The generalized separated electron pair model. 1. An application to NH3

M. A. Robb, I. Csizmadia

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

The utility of the separated electron pair (SEP) model (strongly orthogonal geminals) is examined quantitatively, for pyramidal and planar nuclear configurations of the NH3 molecule. The best SEP wave function computed for each species is capable of recovering about half of the correlation energy obtained by a fairly accurate configuration interaction (CI) calculation, (corresponding to roughly 25% of the total molecular correlation energy). It is illustrated that the model can be systematically extended with only a modest effort to yield more accurate results (about 40% of the total correlation energy). The fact that the corrections to the SEP model have a simple physical interpretation suggests that this model may be a useful starting point for “brute force” CI calculations on larger chemical systems.

Original languageEnglish
Pages (from-to)365-387
Number of pages23
JournalInternational Journal of Quantum Chemistry
Volume4
Issue number4
DOIs
Publication statusPublished - 1970

Fingerprint

Electrons
configuration interaction
electrons
Wave functions
energy
wave functions
Molecules
configurations
molecules

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry

Cite this

The generalized separated electron pair model. 1. An application to NH3 . / Robb, M. A.; Csizmadia, I.

In: International Journal of Quantum Chemistry, Vol. 4, No. 4, 1970, p. 365-387.

Research output: Contribution to journalArticle

@article{0ad088ed12c1467ea943439df0c06551,
title = "The generalized separated electron pair model. 1. An application to NH3",
abstract = "The utility of the separated electron pair (SEP) model (strongly orthogonal geminals) is examined quantitatively, for pyramidal and planar nuclear configurations of the NH3 molecule. The best SEP wave function computed for each species is capable of recovering about half of the correlation energy obtained by a fairly accurate configuration interaction (CI) calculation, (corresponding to roughly 25{\%} of the total molecular correlation energy). It is illustrated that the model can be systematically extended with only a modest effort to yield more accurate results (about 40{\%} of the total correlation energy). The fact that the corrections to the SEP model have a simple physical interpretation suggests that this model may be a useful starting point for “brute force” CI calculations on larger chemical systems.",
author = "Robb, {M. A.} and I. Csizmadia",
year = "1970",
doi = "10.1002/qua.560040404",
language = "English",
volume = "4",
pages = "365--387",
journal = "International Journal of Quantum Chemistry",
issn = "0020-7608",
publisher = "John Wiley and Sons Inc.",
number = "4",

}

TY - JOUR

T1 - The generalized separated electron pair model. 1. An application to NH3

AU - Robb, M. A.

AU - Csizmadia, I.

PY - 1970

Y1 - 1970

N2 - The utility of the separated electron pair (SEP) model (strongly orthogonal geminals) is examined quantitatively, for pyramidal and planar nuclear configurations of the NH3 molecule. The best SEP wave function computed for each species is capable of recovering about half of the correlation energy obtained by a fairly accurate configuration interaction (CI) calculation, (corresponding to roughly 25% of the total molecular correlation energy). It is illustrated that the model can be systematically extended with only a modest effort to yield more accurate results (about 40% of the total correlation energy). The fact that the corrections to the SEP model have a simple physical interpretation suggests that this model may be a useful starting point for “brute force” CI calculations on larger chemical systems.

AB - The utility of the separated electron pair (SEP) model (strongly orthogonal geminals) is examined quantitatively, for pyramidal and planar nuclear configurations of the NH3 molecule. The best SEP wave function computed for each species is capable of recovering about half of the correlation energy obtained by a fairly accurate configuration interaction (CI) calculation, (corresponding to roughly 25% of the total molecular correlation energy). It is illustrated that the model can be systematically extended with only a modest effort to yield more accurate results (about 40% of the total correlation energy). The fact that the corrections to the SEP model have a simple physical interpretation suggests that this model may be a useful starting point for “brute force” CI calculations on larger chemical systems.

UR - http://www.scopus.com/inward/record.url?scp=84987108785&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84987108785&partnerID=8YFLogxK

U2 - 10.1002/qua.560040404

DO - 10.1002/qua.560040404

M3 - Article

VL - 4

SP - 365

EP - 387

JO - International Journal of Quantum Chemistry

JF - International Journal of Quantum Chemistry

SN - 0020-7608

IS - 4

ER -