Long-lived high-spin states of CO2-:: loosely bound complexes between C- and O2

Motivated by the experimental observation of a long-lived CO2- state, we have investigated several sextet states of this species. In analogy to recent results for long-lived sextet states of CO-, we focus on long-range minima of the sextet ground state (6)A(1) of CO2-. We have found two minimum geometries at very long internuclear distances, which can be explained as loosely bound complexes between a C- ion and an oxygen molecule in their respective ground states. Both long-range isomers of the (6)A(1) state are stable with respect to single-electron:emission and dissociation. Since all other decay channels are spin forbidden, these species are long lived.