VTST kinetics study of the N(D-2)+O-2(X-3 Sigma(-)(g)) -> NO(X-2 Pi)+O(P-3,D-1) reactions based on CASSCF and CASPT2 ab initio calculations includingexcited potential energy surfaces

We,have carried out a CASSCF and CASPT2 ab initio study of the N(D-2) + O-2 system, that is very relevant in the upper atmosphere, The saddle points o f the PESs involved in the two reactions that can occur (O(D-1) + NO (1) an d O(P-3) + NO (2)) have been characterized. According to TST and VTST calcu lations performed, the N(D-2) + O-2 reactivity takes place through reaction (2). Also, a good agreement with the experimental kinetics data correspond ing to the global deactivation of N(D-2) has been obtained. These results s uggest that reaction (2) dominates over the physical electronic quenching o f N(D-2). (C) 2001 Elsevier Science B.V. All rights reserved.