A generalized valence bond representation of complete-active-space self-consistent-field (CASSCF) wave functions
Abstract
A novel generalized valence bond wave function expressed in terms of local nonorthogonal orbitals is shown to attain nearly all of the correlation energy of a corresponding complete-active-space self-consistent-field (CASSCF) wave function. This new wave function allows for the local orbitals to variationally respond to different spin couplings. The result is a very compact description of correlation effects contained in complex CASSCF expansions. The CASSCF expansion is also shown to contain a description of resonance among nonorthogonal valence bond structures.
- Publication:
-
Journal of Chemical Physics
- Pub Date:
- May 1993
- DOI:
- 10.1063/1.464550
- Bibcode:
- 1993JChPh..98.7958M