Quantum chemical and theoretical kinetics study of the O[sup.3.P] + [C.sub.2][H.sub.2] reaction: A multistate process

The potential energy surfaces of the two lowest-lying triplet electronic surfaces [sup.3.A'] and [sup.3.A'] for the O[sup.3.P] + [C.sub.2][H.sub.2] reaction were theoretically reinvestigated, using various quantum chemical methods. An efficient reaction pathway on the electronically excited [sup.3.A'] surface resulting in H[sup.2.S] + HCCO[A.sup.2A'] was newly identified and is predicted to play an important role at higher temperatures.