New studies of the unimolecular reaction NO2⇆O+NO.: Part 2.: Relation between high pressure rate constants and potential parameters

The potential energy surfaces of the X 1(2)A'- and C1(2)A "-states of the dissociation/recombination system NO(2)reversible arrow O + NO have been characterized by ab initio methods. Thermal rate constants for the high pressure limit of this reaction have been determined by calculating classical trajectories with simplified representations of the two ab initio potentials. The results well agree with the less accurate experimental data in this temperature range. The treatment is compared with relationships for model valence potentials which were derived earlier. It is demonstrated which parts of the potential are most relevant and to what extent the rate constants could have been predicted without specific ab initio information.