Dynamics of the N(4S)+NO(X 2Π)→N2(X 1Σ+g)+O(3P) atmospheric reaction on the 3A″ ground potential energy surface. III. Quantum dynamical study and comparison with quasiclassical and experimental results

Abstract

A detailed reactive–infinite-order sudden approximation (R-IOSA) study of the reactivity of the N+NO→N2+O system has been carried out in the 0.0038 to 1.388 eV translational energy range and the results have been compared with the existing quasiclassical trajectory (QCT) and experimental data available. The general features already observed in the previous QCT studies are reproduced qualitatively in the quantum study, even though some differences arise in the product vibrational distributions and state-to-state opacity functions in the low energy range. The observed differences have been justified in terms of the anisotropy of the potential energy surface and the vibrational barriers to reaction at fixed angles. A strong vibrational adiabaticity is observed quantally in the low translational energy range, disappearing at moderately high collision energies (around 0.3 eV), where a simple Franck–Condon type model is capable of describing the evolution of the vibrational distribution with translational energy. The vibrational distributions at fixed angles have been discussed within the context of Polanyi’s and Light’s correlation between products vibrational excitation and the features of the potential energy surface. The validity of extending the conclusions drawn from collinear to three-dimensional (3D) collisions is discussed. Finally, the detailed reaction mechanism is examined in light of the vibrational matrix elements of the close-coupling interaction matrix.