Thermal rate constants of the N-2+O->NO+N reaction using ab initio (3)A'' and (3)A' potential energy surfaces

Theoretical determinations of the thermal rate constants and product energy distributions of the N-2+O-->NO+N reaction, which plays a crucial role in hydrocarbon air combustion and high temperature air chemistry, are carried out using a quasiclassical trajectory method. An analytical fit of the lowest (3)A' potential energy surface of this reaction based on the CCI ab initio data is obtained. The trajectory study is done on this surface and an analytical 3A '' surface proposed by Gilibert et al. [J. Chem. Phys. 97, 5542 (1992)]. The thermal rate constants computed from 3000 to 20 000 K are in good agreement with the available experimental data. In addition, the dependence of the rate constant on the N-2 internal state is studied. It is found that a low vibrational excitation can reduce the rate constant of this reaction by a factor of 3. Also, we investigate the effect of the N-2 vibrational state on the product NO vibrational distribution, and it is found that at low Nz vibrational states, the NO vibrational distribution is nearly Boltzmann. However, at N-2(v>10), the product distribution is almost uniform at low energy levels. (C) 1996 American Institute of Physics.