title: Communication: Hartree-Fock description of excited states of H₂.
abstract: Hartree-Fock (HF) theory is most often applied to study the electronic ground states of molecular systems. However, with the advent of numerical techniques for locating higher solutions of the self-consistent field equations, it is now possible to examine the extent to which such mean-field solutions are useful approximations to electronic excited states. In this Communication, we use the maximum overlap method to locate 11 low-energy solutions of the HF equation for the H2 molecule and we find that, with only one exception, these yield surprisingly accurate models for the low-lying excited states of this molecule. This finding suggests that the HF solutions could be useful first-order approximations for correlated excited state wavefunctions.
authors.affiliation: Research School of Chemistry, Australian National University, ACT 0200, Australia.
authors.forename: Giuseppe M J
authors.initials: GM
authors.lastname: Barca
authors.affiliation: Research School of Chemistry, Australian National University, ACT 0200, Australia.
authors.forename: Andrew T B
authors.initials: AT
authors.lastname: Gilbert
authors.affiliation: Research School of Chemistry, Australian National University, ACT 0200, Australia.
authors.forename: Peter M W
authors.initials: PM
authors.lastname: Gill