Reactive and Nonreactive Feshbach Resonances Accessed by Photodetachment of FH2O(-).

The photodetachment of the FH2O(-) anion is investigated quantum mechanically on accurate full-dimensional potential energy surfaces of the two lowest-lying electronic states of FH2O. The calculated photoelectron spectrum possesses both broad and sharp features, corresponding to reactive and nonreactive Feshbach resonances. The former extend to both reactant and product channels over the transition state, while the latter are supported by a hydrogen bonded HO-HF well in the product channel. Many of the resonances are assignable with quantum numbers for the stretching and bending modes of the HO-HF complex as well as the H-F vibration. The implications of these resonances in the F + H2O ↔ HF + HO reaction are discussed.