Use of symmetry-adapted Brillouin theorem to analyze the variational content of molecular wave functions along potential energy surfaces: Application to BH2 and PO2
✍ Scribed by Jacques Liévin; Nathalie Vaeck
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 308 KB
- Volume
- 62
- Category
- Article
- ISSN
- 0020-7608
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✦ Synopsis
The analysis of the Brillouin conditions in a chain of groups is used to Ž . Ž . explain why self-consistent field SCF , multiconfigurational SCF MCSCF , or Ž . configuration interaction CI methods can lead to an unbalanced description of the potential energy hypersurfaces along symmetry-broken pathways. A Wigner᎐Racah formulation of the generalized Brillouin theorem is the appropriate theoretical tool for performing such an analysis. We apply this procedure to a Renner᎐Teller splitting in BH 2 and to a pseudo-Jahn᎐Teller conical intersection in PO . A systematic ab initio study of 2 both systems leads to the definition of compact CASSCF wave functions which ensure a balanced description of the ground Born᎐Oppenheimer potential energy surfaces.