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dc.contributor.authorStein, Tamar
Henderson, Thomas M.
Scuseria, Gustavo E.
dc.date.accessioned 2017-05-24T16:33:36Z
dc.date.available 2017-05-24T16:33:36Z
dc.date.issued 2014
dc.identifier.citation Stein, Tamar, Henderson, Thomas M. and Scuseria, Gustavo E.. "Seniority zero pair coupled cluster doubles theory." The Journal of Chemical Physics, 140, no. 21 (2014) AIP Publishing: http://dx.doi.org/10.1063/1.4880819.
dc.identifier.urihttps://hdl.handle.net/1911/94381
dc.description.abstract Coupled clusterᅠtheoryᅠwith single and doubleᅠexcitationsᅠaccurately describes weak electronᅠcorrelationᅠbut is known to fail in cases of strong staticᅠcorrelation.ᅠFascinatingly, however, pairᅠcoupled clusterᅠdoubles (p-CCD), a simplified version of theᅠtheoryᅠlimited to pairᅠexcitationsᅠthat preserve the seniority of the reference determinant (i.e.,ᅠthe number of unpaired electrons), hasᅠmean fieldᅠcomputational cost and is an excellent approximation to the full configuration interaction (FCI) of the paired space provided that the orbital basis defining the pairing scheme is adequately optimized. In previous work, we have shown that optimization of the pairing scheme in the seniority zero FCI leads to a very accurate description of staticᅠcorrelation.ᅠThe same conclusion extends to p-CCD if the orbitals are optimized to make the p-CCD energy stationary. We here demonstrate these results with numerous examples. We also explore the contributions of different seniority sectors to theᅠcoupled clusterᅠdoublesᅠ(CCD)ᅠcorrelationᅠenergy using different orbital bases. We consider both Hartree-Fock and Brueckner orbitals, and the role of orbital localization. We show how one can pair the orbitals so that the role of the Brueckner orbitals at theᅠCCDᅠlevel is retained at the p-CCD level. Moreover, we explore ways of extendingᅠCCDᅠto accurately describe strongly correlated systems.
dc.language.iso eng
dc.publisher AIP Publishing
dc.rights Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
dc.title Seniority zero pair coupled cluster doubles theory
dc.type Journal article
dc.citation.journalTitle The Journal of Chemical Physics
dc.citation.volumeNumber 140
dc.citation.issueNumber 21
dc.type.dcmi Text
dc.identifier.doihttp://dx.doi.org/10.1063/1.4880819
dc.identifier.pmid 24907996
dc.type.publication publisher version
dc.citation.articleNumber 214113


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