Optimized partitioning in Rayleigh-Schrödinger perturbation theory

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Finite-order perturbation corrections are ambiguous since they depend on the partitioning of the Hamiltonian to a zero-order part and perturbation, and any chosen partitioning can be freely modified, e.g. by level shift projectors. To optimize low-order corrections, an approximate variational procedure is proposed to determine level shift parameters from the first-order Ansatz for the wavefunction. The resulting new partitioning scheme provides significantly better second-order results than those obtained by standard partitions like Epstein-Nesbet or Møller-Plesset. We treat the anharmonic oscillator and the atomic electron correlation energy in He, Be and Ne as numerical test cases.

Original languageEnglish
Pages (from-to)303-309
Number of pages7
JournalChemical Physics Letters
Volume308
Issue number3-4
Publication statusPublished - Jul 23 1999

Fingerprint

Hamiltonians
Electron correlations
Wave functions
perturbation theory
perturbation
shift
projectors
partitions
oscillators
electrons
energy

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Spectroscopy
  • Atomic and Molecular Physics, and Optics

Cite this

Optimized partitioning in Rayleigh-Schrödinger perturbation theory. / Szabados, Á; Surján, P. R.

In: Chemical Physics Letters, Vol. 308, No. 3-4, 23.07.1999, p. 303-309.

Research output: Contribution to journalArticle

@article{c6a021b11fe5453f8e5d3011a5b342ce,
title = "Optimized partitioning in Rayleigh-Schr{\"o}dinger perturbation theory",
abstract = "Finite-order perturbation corrections are ambiguous since they depend on the partitioning of the Hamiltonian to a zero-order part and perturbation, and any chosen partitioning can be freely modified, e.g. by level shift projectors. To optimize low-order corrections, an approximate variational procedure is proposed to determine level shift parameters from the first-order Ansatz for the wavefunction. The resulting new partitioning scheme provides significantly better second-order results than those obtained by standard partitions like Epstein-Nesbet or M{\o}ller-Plesset. We treat the anharmonic oscillator and the atomic electron correlation energy in He, Be and Ne as numerical test cases.",
author = "{\'A} Szabados and Surj{\'a}n, {P. R.}",
year = "1999",
month = "7",
day = "23",
language = "English",
volume = "308",
pages = "303--309",
journal = "Chemical Physics Letters",
issn = "0009-2614",
publisher = "Elsevier",
number = "3-4",

}

TY - JOUR

T1 - Optimized partitioning in Rayleigh-Schrödinger perturbation theory

AU - Szabados, Á

AU - Surján, P. R.

PY - 1999/7/23

Y1 - 1999/7/23

N2 - Finite-order perturbation corrections are ambiguous since they depend on the partitioning of the Hamiltonian to a zero-order part and perturbation, and any chosen partitioning can be freely modified, e.g. by level shift projectors. To optimize low-order corrections, an approximate variational procedure is proposed to determine level shift parameters from the first-order Ansatz for the wavefunction. The resulting new partitioning scheme provides significantly better second-order results than those obtained by standard partitions like Epstein-Nesbet or Møller-Plesset. We treat the anharmonic oscillator and the atomic electron correlation energy in He, Be and Ne as numerical test cases.

AB - Finite-order perturbation corrections are ambiguous since they depend on the partitioning of the Hamiltonian to a zero-order part and perturbation, and any chosen partitioning can be freely modified, e.g. by level shift projectors. To optimize low-order corrections, an approximate variational procedure is proposed to determine level shift parameters from the first-order Ansatz for the wavefunction. The resulting new partitioning scheme provides significantly better second-order results than those obtained by standard partitions like Epstein-Nesbet or Møller-Plesset. We treat the anharmonic oscillator and the atomic electron correlation energy in He, Be and Ne as numerical test cases.

UR - http://www.scopus.com/inward/record.url?scp=0000257285&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0000257285&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0000257285

VL - 308

SP - 303

EP - 309

JO - Chemical Physics Letters

JF - Chemical Physics Letters

SN - 0009-2614

IS - 3-4

ER -