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A spin-complete version of the spin-flip approach to bond breaking: What is the impact of obtaining spin eigenfunctions?

J. Chem. Phys. 118, 9084 (2003); doi:10.1063/1.1568735

Issue Date: 22 May 2003

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John S. Sears and C. David Sherrill
Center for Computational Molecular Science and Technology, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400

Anna I. Krylov
Department of Chemistry, University of Southern California, Los Angeles, California 90089-1062
Spin-complete versions of the spin-flip configuration-interaction-singles (SF-CIS) approach have been investigated to determine the impact of making the wave function an eigenfunction of S-hat2. The method has been implemented within an extended restricted active space configuration interaction formalism. Spin-complete results are presented for excitation energies, equilibrium geometries, and potential energy curves for dissociation of a single bond in several small molecules. The effect of different orbital choices has also been investigated. The spin-complete results are compared both to results using the original spin-flip method and to more computationally expensive benchmarks. Using spin eigenfunctions dramatically improves upon the accuracy of the SF-CIS approach. ©2003 American Institute of Physics.
History: Received 2 January 2003; accepted 27 February 2003
Permalink: http://link.aip.org/link/?JCPSA6/118/9084/1
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KEYWORDS and PACS

Keywords
PACS
  • 31.25.-v
    Electron correlation calculations for atoms and molecules
  • 82.30.Lp
    Decomposition chemical reactions (pyrolysis, dissociation, and fragmentation)
  • 82.20.Kh
    Potential energy surfaces for chemical reactions
  • 82.37.Np
    Single molecule reaction kinetics, dissociation, etc
  • YEAR: 2003

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PUBLICATION DATA

ISSN:
0021-9606 (print)   1089-7690 (online)
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REFERENCES (26)
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