Reactive and Nonreactive Collisions between NO(X 2 Π) and O( 3 P) under Hyperthermal Conditions.

Quasiclassical trajectory calculations are performed for hyperthermal collisions between NO(X 2 Π) and O( 3 P) on recently developed potential energy surfaces for the lowest doublet and quartet states of the NO 2 system. Three product channels are investigated, and their branching fractions are in reasonably good agreement with the recent crossed molecular beam study at 84 kcal/mol of collision energy. The dominant inelastic channel has a strong forward scattering bias and a high translational energy distribution with limited internal excitation in the scattered NO. The exchange channel has significantly higher NO internal excitation and is also forward biased. The abstraction channel producing internally excited O 2 has the smallest branching fraction and a broader angular distribution also with a forward peak. The angular and translational energy distributions in the three channels are consistent with experiment, but the agreement is not always quantitative. The sources of the differences are discussed. Finally, the impact of NO vibrational excitation on the reactive channels and the corresponding rate coefficients are reported.