The 1A 1 electronic excited states of H 2CS: an ab initio MRD CI study

Abstract

Ab initio CI studies have been performed to determine the energies of the lowest five 1A 1 states of thioformaldehyde, H 2CS, as a function of CS distance in C 2v symmetry. In addition to the well-known Rydberg and 1π,π* states, a doubly excited state of n 0, π* 2 configuration has been found which, at ground-state equilibrium geometry, lies very close to the π, π* state. The chemical and spectroscopic implications of this state are discussed.