Mechanistic insights into the H + O 2 → OH + O reaction from quasi-classical trajectory studies on a new ab initio potential energy surface

Abstract

We report quasi-classical trajectory studies of the title reaction on a new potential energy surface based on high-level ab initio data. At moderately high energies, the differential cross section was found to be near symmetric, but with increasing collision energy it becomes strongly forward biased. The forward–backward symmetry, however, does not prove to be a strict indication of complex formation as such angular distributions are observed at relatively low collision energies even if the lifetime of the complex is very short. The lifetime distribution of the collision complexes is not exponential. Strong signs of statistical behavior are observed only in the ensemble of complexes living for 2.5 ps or longer.