### Abstract

Two perturbation (PT) theories are developed starting from a multiconfiguration (MC) zero-order function. To span the configuration space, the theories employ biorthogonal vector sets introduced in the MCPT framework. At odds with previous formulations, the present construction operates with the full Fockian corresponding to a principal determinant, giving rise to a nondiagonal matrix of the zero-order resolvent. The theories provide a simple, generalized Møller-Plesset (MP) second-order correction to improve any reference function, corresponding either to a complete or incomplete model space. Computational demand of the procedure is determined by the iterative inversion of the Fockian, similarly to the single reference MP theory calculated in a localized basis. Relation of the theory to existing multireference (MR) PT formalisms is discussed. The performance of the present theories is assessed by adopting the antisymmetric product of strongly orthogonal geminal (APSG) wave functions as the reference function.

Original language | English |
---|---|

Pages (from-to) | 2024-2033 |

Number of pages | 10 |

Journal | Journal of Chemical Theory and Computation |

Volume | 6 |

Issue number | 7 |

DOIs | |

Publication status | Published - júl. 13 2010 |

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### ASJC Scopus subject areas

- Physical and Theoretical Chemistry
- Computer Science Applications

### Cite this

*Journal of Chemical Theory and Computation*,

*6*(7), 2024-2033. https://doi.org/10.1021/ct1001939

**Generalized Møller-Plesset partitioning in multiconfiguration perturbation theory.** / Kobayashi, Masato; Szabados, A.; Nakai, Hiromi; Surján, P.

Research output: Article

*Journal of Chemical Theory and Computation*, vol. 6, no. 7, pp. 2024-2033. https://doi.org/10.1021/ct1001939

}

TY - JOUR

T1 - Generalized Møller-Plesset partitioning in multiconfiguration perturbation theory

AU - Kobayashi, Masato

AU - Szabados, A.

AU - Nakai, Hiromi

AU - Surján, P.

PY - 2010/7/13

Y1 - 2010/7/13

N2 - Two perturbation (PT) theories are developed starting from a multiconfiguration (MC) zero-order function. To span the configuration space, the theories employ biorthogonal vector sets introduced in the MCPT framework. At odds with previous formulations, the present construction operates with the full Fockian corresponding to a principal determinant, giving rise to a nondiagonal matrix of the zero-order resolvent. The theories provide a simple, generalized Møller-Plesset (MP) second-order correction to improve any reference function, corresponding either to a complete or incomplete model space. Computational demand of the procedure is determined by the iterative inversion of the Fockian, similarly to the single reference MP theory calculated in a localized basis. Relation of the theory to existing multireference (MR) PT formalisms is discussed. The performance of the present theories is assessed by adopting the antisymmetric product of strongly orthogonal geminal (APSG) wave functions as the reference function.

AB - Two perturbation (PT) theories are developed starting from a multiconfiguration (MC) zero-order function. To span the configuration space, the theories employ biorthogonal vector sets introduced in the MCPT framework. At odds with previous formulations, the present construction operates with the full Fockian corresponding to a principal determinant, giving rise to a nondiagonal matrix of the zero-order resolvent. The theories provide a simple, generalized Møller-Plesset (MP) second-order correction to improve any reference function, corresponding either to a complete or incomplete model space. Computational demand of the procedure is determined by the iterative inversion of the Fockian, similarly to the single reference MP theory calculated in a localized basis. Relation of the theory to existing multireference (MR) PT formalisms is discussed. The performance of the present theories is assessed by adopting the antisymmetric product of strongly orthogonal geminal (APSG) wave functions as the reference function.

UR - http://www.scopus.com/inward/record.url?scp=79251649917&partnerID=8YFLogxK

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U2 - 10.1021/ct1001939

DO - 10.1021/ct1001939

M3 - Article

VL - 6

SP - 2024

EP - 2033

JO - Journal of Chemical Theory and Computation

JF - Journal of Chemical Theory and Computation

SN - 1549-9618

IS - 7

ER -