A configuration interaction (CI) method by use of natural orbitals (NO) derived from the generalized Hartree-Fock (GHF) solutions is proposed and applied to trimethylene as an example. It is found that the GHF NO CI method is equivalent to the traditional restricted HF (RHF) CI approach in the domain of weak correlation, and is similar to the generalized VB (GVB) CI method in the strong-correlation region. The GHF NO CI method thus seems to be promising for the study of the electronic structure of unstable molecules which are characterized by orbital and spin degeneracies.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry