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Title: Cluster expansion of the wavefunction. Symmetry-adapted-cluster expansion, its variational determination, and extension of open-shell orbital theory

Abstract

The symmetry-adapted-cluster (SAC) expansion of an exact wavefunction is given. It is constructed from the generators of the symmetry-adapted excited configurations having the symmetry under consideration, and includes their higher-order effect and self-consistency effect. It is different from the conventional cluster expansions in several important points, and is suitable for applications to open-shell systems as well as closed-shell systems. The variational equation for the SAC wavefunction has a form similar to the generalized Brillouin theorem in accordance with the inclusion of the higher-order effect and the self-consistency effect. We have expressed some existing open-shell orbital theories equivalently in the conventional cluster expansion formulas, and on this basis, we have given the pseudo-orbital theory which is an extension of open-shell orbital theory in the SAC expansion formula.

Authors:
;
Publication Date:
Research Org.:
Department of Hydrocarbon Chemistry, Faculty of Engineering, Kyoto University, Kyoto, Japan and Department of Chemistry, Shiga University of Medical Science, Seta, Otsu, Japan
OSTI Identifier:
5065657
Resource Type:
Journal Article
Journal Name:
J. Chem. Phys.; (United States)
Additional Journal Information:
Journal Volume: 68:5
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; WAVE FUNCTIONS; CLUSTER EXPANSION; ELECTRONIC STRUCTURE; EXCITED STATES; VARIATIONAL METHODS; ENERGY LEVELS; FUNCTIONS; 640305* - Atomic, Molecular & Chemical Physics- Atomic & Molecular Theory- (-1987)

Citation Formats

Nakatsuji, H, and Hirao, K. Cluster expansion of the wavefunction. Symmetry-adapted-cluster expansion, its variational determination, and extension of open-shell orbital theory. United States: N. p., 1978. Web. doi:10.1063/1.436028.
Nakatsuji, H, & Hirao, K. Cluster expansion of the wavefunction. Symmetry-adapted-cluster expansion, its variational determination, and extension of open-shell orbital theory. United States. https://doi.org/10.1063/1.436028
Nakatsuji, H, and Hirao, K. 1978. "Cluster expansion of the wavefunction. Symmetry-adapted-cluster expansion, its variational determination, and extension of open-shell orbital theory". United States. https://doi.org/10.1063/1.436028.
@article{osti_5065657,
title = {Cluster expansion of the wavefunction. Symmetry-adapted-cluster expansion, its variational determination, and extension of open-shell orbital theory},
author = {Nakatsuji, H and Hirao, K},
abstractNote = {The symmetry-adapted-cluster (SAC) expansion of an exact wavefunction is given. It is constructed from the generators of the symmetry-adapted excited configurations having the symmetry under consideration, and includes their higher-order effect and self-consistency effect. It is different from the conventional cluster expansions in several important points, and is suitable for applications to open-shell systems as well as closed-shell systems. The variational equation for the SAC wavefunction has a form similar to the generalized Brillouin theorem in accordance with the inclusion of the higher-order effect and the self-consistency effect. We have expressed some existing open-shell orbital theories equivalently in the conventional cluster expansion formulas, and on this basis, we have given the pseudo-orbital theory which is an extension of open-shell orbital theory in the SAC expansion formula.},
doi = {10.1063/1.436028},
url = {https://www.osti.gov/biblio/5065657}, journal = {J. Chem. Phys.; (United States)},
number = ,
volume = 68:5,
place = {United States},
year = {Wed Mar 01 00:00:00 EST 1978},
month = {Wed Mar 01 00:00:00 EST 1978}
}