Multireference averaged quadratic coupled-cluster (MR-AQCC) method based on the functional of the total energy

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

In this short paper a new version of the multireference (MR) averaged coupled pair functional (ACPF) and the MR averaged quadratic coupled-cluster (AQCC) methods is presented which corrects the failure of the original formulation in case of close-lying states described with small reference space. This new version is based on a functional which also includes the reference energy, i.e. instead of optimizing the correlation energy, the total energy will be made stationary with respect the wave function parameters. It is demonstrated that this method gives smooth potential energy surfaces in case of avoided crossings.

Original languageEnglish
Pages (from-to)121-125
Number of pages5
JournalChemical Physics
Volume349
Issue number1-3
DOIs
Publication statusPublished - Jun 16 2008

Fingerprint

Potential energy surfaces
Wave functions
energy
potential energy
wave functions
formulations

Keywords

  • Ab initio
  • Avoided crossing
  • Electron correlation
  • Size-consistency

ASJC Scopus subject areas

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

Cite this

Multireference averaged quadratic coupled-cluster (MR-AQCC) method based on the functional of the total energy. / Szalay, P.

In: Chemical Physics, Vol. 349, No. 1-3, 16.06.2008, p. 121-125.

Research output: Contribution to journalArticle

@article{5bd644a9b9cb4dfba37b198a562bd2cc,
title = "Multireference averaged quadratic coupled-cluster (MR-AQCC) method based on the functional of the total energy",
abstract = "In this short paper a new version of the multireference (MR) averaged coupled pair functional (ACPF) and the MR averaged quadratic coupled-cluster (AQCC) methods is presented which corrects the failure of the original formulation in case of close-lying states described with small reference space. This new version is based on a functional which also includes the reference energy, i.e. instead of optimizing the correlation energy, the total energy will be made stationary with respect the wave function parameters. It is demonstrated that this method gives smooth potential energy surfaces in case of avoided crossings.",
keywords = "Ab initio, Avoided crossing, Electron correlation, Size-consistency",
author = "P. Szalay",
year = "2008",
month = "6",
day = "16",
doi = "10.1016/j.chemphys.2008.03.011",
language = "English",
volume = "349",
pages = "121--125",
journal = "Chemical Physics",
issn = "0301-0104",
publisher = "Elsevier",
number = "1-3",

}

TY - JOUR

T1 - Multireference averaged quadratic coupled-cluster (MR-AQCC) method based on the functional of the total energy

AU - Szalay, P.

PY - 2008/6/16

Y1 - 2008/6/16

N2 - In this short paper a new version of the multireference (MR) averaged coupled pair functional (ACPF) and the MR averaged quadratic coupled-cluster (AQCC) methods is presented which corrects the failure of the original formulation in case of close-lying states described with small reference space. This new version is based on a functional which also includes the reference energy, i.e. instead of optimizing the correlation energy, the total energy will be made stationary with respect the wave function parameters. It is demonstrated that this method gives smooth potential energy surfaces in case of avoided crossings.

AB - In this short paper a new version of the multireference (MR) averaged coupled pair functional (ACPF) and the MR averaged quadratic coupled-cluster (AQCC) methods is presented which corrects the failure of the original formulation in case of close-lying states described with small reference space. This new version is based on a functional which also includes the reference energy, i.e. instead of optimizing the correlation energy, the total energy will be made stationary with respect the wave function parameters. It is demonstrated that this method gives smooth potential energy surfaces in case of avoided crossings.

KW - Ab initio

KW - Avoided crossing

KW - Electron correlation

KW - Size-consistency

UR - http://www.scopus.com/inward/record.url?scp=44749088749&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=44749088749&partnerID=8YFLogxK

U2 - 10.1016/j.chemphys.2008.03.011

DO - 10.1016/j.chemphys.2008.03.011

M3 - Article

AN - SCOPUS:44749088749

VL - 349

SP - 121

EP - 125

JO - Chemical Physics

JF - Chemical Physics

SN - 0301-0104

IS - 1-3

ER -