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The restricted active space followed by second-order perturbation theory method: Theory and application to the study of CuO(2) and Cu(2)O(2) systems.

Malmqvist, Per-Åke LU ; Pierloot, Kristine ; Shahi, Abdul Rehaman Moughal ; Cramer, Christopher J and Gagliardi, Laura (2008) In Journal of Chemical Physics 128(20).
Abstract
A multireference second-order perturbation theory using a restricted active space self-consistent field wave function as reference (RASPT2/RASSCF) is described. This model is particularly effective for cases where a chemical system requires a balanced orbital active space that is too large to be addressed by the complete active space self-consistent field model with or without second-order perturbation theory (CASPT2 or CASSCF, respectively). Rather than permitting all possible electronic configurations of the electrons in the active space to appear in the reference wave function, certain orbitals are sequestered into two subspaces that permit a maximum number of occupations or holes, respectively, in any given configuration, thereby... (More)
A multireference second-order perturbation theory using a restricted active space self-consistent field wave function as reference (RASPT2/RASSCF) is described. This model is particularly effective for cases where a chemical system requires a balanced orbital active space that is too large to be addressed by the complete active space self-consistent field model with or without second-order perturbation theory (CASPT2 or CASSCF, respectively). Rather than permitting all possible electronic configurations of the electrons in the active space to appear in the reference wave function, certain orbitals are sequestered into two subspaces that permit a maximum number of occupations or holes, respectively, in any given configuration, thereby reducing the total number of possible configurations. Subsequent second-order perturbation theory captures additional dynamical correlation effects. Applications of the theory to the electronic structure of complexes involved in the activation of molecular oxygen by mono- and binuclear copper complexes are presented. In the mononuclear case, RASPT2 and CASPT2 provide very similar results. In the binuclear cases, however, only RASPT2 proves quantitatively useful, owing to the very large size of the necessary active space. (Less)
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; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Chemical Physics
volume
128
issue
20
article number
204109
publisher
American Institute of Physics (AIP)
external identifiers
  • wos:000256304200013
  • pmid:18513012
  • scopus:44649111460
  • pmid:18513012
ISSN
0021-9606
DOI
10.1063/1.2920188
language
English
LU publication?
yes
additional info
The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Theoretical Chemistry (S) (011001039)
id
4154ca77-c513-4160-aeb8-5e593ef7bd49 (old id 1169408)
date added to LUP
2016-04-01 12:35:39
date last changed
2023-04-05 18:17:54
@article{4154ca77-c513-4160-aeb8-5e593ef7bd49,
  abstract     = {{A multireference second-order perturbation theory using a restricted active space self-consistent field wave function as reference (RASPT2/RASSCF) is described. This model is particularly effective for cases where a chemical system requires a balanced orbital active space that is too large to be addressed by the complete active space self-consistent field model with or without second-order perturbation theory (CASPT2 or CASSCF, respectively). Rather than permitting all possible electronic configurations of the electrons in the active space to appear in the reference wave function, certain orbitals are sequestered into two subspaces that permit a maximum number of occupations or holes, respectively, in any given configuration, thereby reducing the total number of possible configurations. Subsequent second-order perturbation theory captures additional dynamical correlation effects. Applications of the theory to the electronic structure of complexes involved in the activation of molecular oxygen by mono- and binuclear copper complexes are presented. In the mononuclear case, RASPT2 and CASPT2 provide very similar results. In the binuclear cases, however, only RASPT2 proves quantitatively useful, owing to the very large size of the necessary active space.}},
  author       = {{Malmqvist, Per-Åke and Pierloot, Kristine and Shahi, Abdul Rehaman Moughal and Cramer, Christopher J and Gagliardi, Laura}},
  issn         = {{0021-9606}},
  language     = {{eng}},
  number       = {{20}},
  publisher    = {{American Institute of Physics (AIP)}},
  series       = {{Journal of Chemical Physics}},
  title        = {{The restricted active space followed by second-order perturbation theory method: Theory and application to the study of CuO(2) and Cu(2)O(2) systems.}},
  url          = {{http://dx.doi.org/10.1063/1.2920188}},
  doi          = {{10.1063/1.2920188}},
  volume       = {{128}},
  year         = {{2008}},
}