Seniority zero pair coupled cluster doubles theory
| dc.citation.articleNumber | 214113 | |
| dc.citation.issueNumber | 21 | |
| dc.citation.journalTitle | The Journal of Chemical Physics | |
| dc.citation.volumeNumber | 140 | |
| dc.contributor.author | Stein, Tamar | |
| dc.contributor.author | Henderson, Thomas M. | |
| dc.contributor.author | Scuseria, Gustavo E. | |
| dc.date.accessioned | 2017-05-24T16:33:36Z | |
| dc.date.available | 2017-05-24T16:33:36Z | |
| dc.date.issued | 2014 | |
| 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.identifier.citation | Stein, Tamar, Henderson, Thomas M. and Scuseria, Gustavo E.. "Seniority zero pair coupled cluster doubles theory." <i>The Journal of Chemical Physics,</i> 140, no. 21 (2014) AIP Publishing: http://dx.doi.org/10.1063/1.4880819. | |
| dc.identifier.doi | http://dx.doi.org/10.1063/1.4880819 | |
| dc.identifier.uri | https://hdl.handle.net/1911/94381 | |
| 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.type.dcmi | Text | |
| dc.type.publication | publisher version |
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