Ring coupled-cluster doubles correction to geminal wavefunctions

A. Szabados, Ádám Margócsy

Research output: Article

1 Citation (Scopus)

Abstract

A ring approximation in coupled-cluster (CC) theory is worked out at the multireference (MR) level. The underlying CC framework is based on generalised normal ordering and applies the corresponding generalised Wick's theorem. Contractions among cluster operators are avoided by adopting a normal ordered exponential Ansatz. The MR ring CC doubles (MR rCCD) theory is found to represent a companion to the previously introduced extended random phase approximation (ERPA). Equations for wavefunction parameters are derived in parallel and compared. Condition for the ground state consistent with ERPA is obtained. This paves the way towards comparison with the ERPA-based correction to the antisymmetrised product of strongly orthogonal geminal (APSG) reference, ERPA-APSG.

Original languageEnglish
Pages (from-to)2731-2742
Number of pages12
JournalMolecular Physics
Volume115
Issue number21-22
DOIs
Publication statusPublished - nov. 17 2017

Fingerprint

Capillary Action
Wave functions
Ground state
rings
approximation
wicks
products
contraction
theorems
operators
ground state

ASJC Scopus subject areas

  • Biophysics
  • Molecular Biology
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry

Cite this

Ring coupled-cluster doubles correction to geminal wavefunctions. / Szabados, A.; Margócsy, Ádám.

In: Molecular Physics, Vol. 115, No. 21-22, 17.11.2017, p. 2731-2742.

Research output: Article

Szabados, A. ; Margócsy, Ádám. / Ring coupled-cluster doubles correction to geminal wavefunctions. In: Molecular Physics. 2017 ; Vol. 115, No. 21-22. pp. 2731-2742.
@article{24f295b27a8542cc857b0aba57dd37d1,
title = "Ring coupled-cluster doubles correction to geminal wavefunctions",
abstract = "A ring approximation in coupled-cluster (CC) theory is worked out at the multireference (MR) level. The underlying CC framework is based on generalised normal ordering and applies the corresponding generalised Wick's theorem. Contractions among cluster operators are avoided by adopting a normal ordered exponential Ansatz. The MR ring CC doubles (MR rCCD) theory is found to represent a companion to the previously introduced extended random phase approximation (ERPA). Equations for wavefunction parameters are derived in parallel and compared. Condition for the ground state consistent with ERPA is obtained. This paves the way towards comparison with the ERPA-based correction to the antisymmetrised product of strongly orthogonal geminal (APSG) reference, ERPA-APSG.",
keywords = "geminal wavefunction, generalised Wick's theorem, random phase approximation, multireference approach, Ring coupled-cluster doubles",
author = "A. Szabados and {\'A}d{\'a}m Marg{\'o}csy",
year = "2017",
month = "11",
day = "17",
doi = "10.1080/00268976.2017.1317111",
language = "English",
volume = "115",
pages = "2731--2742",
journal = "Molecular Physics",
issn = "0026-8976",
publisher = "Taylor and Francis Ltd.",
number = "21-22",

}

TY - JOUR

T1 - Ring coupled-cluster doubles correction to geminal wavefunctions

AU - Szabados, A.

AU - Margócsy, Ádám

PY - 2017/11/17

Y1 - 2017/11/17

N2 - A ring approximation in coupled-cluster (CC) theory is worked out at the multireference (MR) level. The underlying CC framework is based on generalised normal ordering and applies the corresponding generalised Wick's theorem. Contractions among cluster operators are avoided by adopting a normal ordered exponential Ansatz. The MR ring CC doubles (MR rCCD) theory is found to represent a companion to the previously introduced extended random phase approximation (ERPA). Equations for wavefunction parameters are derived in parallel and compared. Condition for the ground state consistent with ERPA is obtained. This paves the way towards comparison with the ERPA-based correction to the antisymmetrised product of strongly orthogonal geminal (APSG) reference, ERPA-APSG.

AB - A ring approximation in coupled-cluster (CC) theory is worked out at the multireference (MR) level. The underlying CC framework is based on generalised normal ordering and applies the corresponding generalised Wick's theorem. Contractions among cluster operators are avoided by adopting a normal ordered exponential Ansatz. The MR ring CC doubles (MR rCCD) theory is found to represent a companion to the previously introduced extended random phase approximation (ERPA). Equations for wavefunction parameters are derived in parallel and compared. Condition for the ground state consistent with ERPA is obtained. This paves the way towards comparison with the ERPA-based correction to the antisymmetrised product of strongly orthogonal geminal (APSG) reference, ERPA-APSG.

KW - geminal wavefunction

KW - generalised Wick's theorem, random phase approximation

KW - multireference approach

KW - Ring coupled-cluster doubles

UR - http://www.scopus.com/inward/record.url?scp=85019050811&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85019050811&partnerID=8YFLogxK

U2 - 10.1080/00268976.2017.1317111

DO - 10.1080/00268976.2017.1317111

M3 - Article

AN - SCOPUS:85019050811

VL - 115

SP - 2731

EP - 2742

JO - Molecular Physics

JF - Molecular Physics

SN - 0026-8976

IS - 21-22

ER -