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A multireference coupled-electron pair approximation combined with complete-active space perturbation theory in local pair-natural orbital framework
http://hdl.handle.net/2237/00032518
http://hdl.handle.net/2237/000325182a93d703-3c62-4f7c-937c-359fa42af746
名前 / ファイル | ライセンス | アクション |
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1_5142622 (1.6 MB)
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Item type | 学術雑誌論文 / Journal Article(1) | |||||
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公開日 | 2020-07-16 | |||||
タイトル | ||||||
タイトル | A multireference coupled-electron pair approximation combined with complete-active space perturbation theory in local pair-natural orbital framework | |||||
言語 | en | |||||
著者 |
Saitow, Masaaki
× Saitow, Masaaki× Yanai, Takeshi |
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アクセス権 | ||||||
アクセス権 | open access | |||||
アクセス権URI | http://purl.org/coar/access_right/c_abf2 | |||||
権利 | ||||||
言語 | en | |||||
権利情報 | Copyright 2020 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing.The following article appeared in (The Journal of Chemical Physics. v.152, n.11, 2020, p.114111) and may be found at (http://dx.doi.org/10.1063/1.5142622). | |||||
抄録 | ||||||
内容記述タイプ | Abstract | |||||
内容記述 | The Complete-Active Space Second-order Perturbation Theory (CASPT2) has been one of the most widely-used methods for reliably calculating electronic structures of multireference systems. Because of its lowest level treatment of dynamic correlation, it has a high computational feasibility; however, its accuracy in some cases falls short of needs. Here, as a simple yet higher-order alternative, we introduce a hybrid theory of the CASPT2 and a multireference variant of the Coupled-Electron Pair Approximation (CEPA), which is a class of high level correlation theory. A central feature of our theory (CEPT2) is to use the two underlying theories for describing different divisions of correlation components based on the full internal contraction framework. The external components, which usually give a major contribution to the dynamic correlation, are intensively described using the CEPA Ansatz, while the rests are treated at the CASPT2 level. Furthermore, to drastically reduce the computational demands, we have incorporated the pair-natural orbital (PNO) method into our multireference implementations. This development, thus, requires highly complex derivations and coding, while it has been largely facilitated with an automatic expression and code generation technique. To highlight the accuracy of the CEPT2 approach and to assess the errors caused by the PNO truncation, benchmark calculations are shown on small- to medium-size molecules, illustrating the high accuracy of the present CEPT2 model. By tightening the truncation thresholds, the PNO-CEPT2 energy converges toward the canonical counterpart and is more accurate than that of PNO-CASPT2 as long as the same truncation thresholds are used. | |||||
言語 | en | |||||
内容記述 | ||||||
内容記述タイプ | Other | |||||
内容記述 | ファイル公開:2021/03/21 | |||||
言語 | ja | |||||
出版者 | ||||||
出版者 | AIP Publishing | |||||
言語 | en | |||||
言語 | ||||||
言語 | eng | |||||
資源タイプ | ||||||
資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||
資源タイプ | journal article | |||||
出版タイプ | ||||||
出版タイプ | VoR | |||||
出版タイプResource | http://purl.org/coar/version/c_970fb48d4fbd8a85 | |||||
DOI | ||||||
関連タイプ | isVersionOf | |||||
識別子タイプ | DOI | |||||
関連識別子 | https://doi.org/10.1063/1.5142622 | |||||
ISSN(print) | ||||||
収録物識別子タイプ | PISSN | |||||
収録物識別子 | 0021-9606 | |||||
書誌情報 |
en : The Journal of Chemical Physics 巻 152, 号 11, p. 114111, 発行日 2020-03-21 |
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著者版フラグ | ||||||
値 | publisher |