Quasiclassical dynamics and kinetics of the N + NO → N+O, NO+N atmospheric reactions

Abstract

The kinetics and dynamics of the title reactions was studied, using the quasiclassical trajectory (QCT) method and two ab initio analytical potential energy surfaces (PESs) developed by our group. In addition to the rate constant (T: 10-5000 K), we also considered a broad set of dynamic properties as a function of collision energy (up to 1.0 eV) and the rovibrational state of NO(v=0-2,j=1,8,12). The production of N2 + O, reaction (1), dominates the reactivity of the N + NO system over the conditions studied, as expected from the large energy barriers associated to the NO + N exchange reaction, reaction (2). Moreover, the ground PES, which is barrierless for reaction (1), plays a dominant role. Most of the results were interpreted according to the properties of the PESs involved and the kinematics of the system. The QCT rate constants of reaction (1) are in agreement with the experimental data (T: 47-3500 K), including very recent low temperature measurements, and also with variational transition state kinetics and most of quantum dynamics calculations. In addition, the QCT average vibrational energy content of the N2 product also agrees with the experimental and quantum data. The PESs used here could also be useful to determine equilibrium and non-equilibrium reaction rates at very high temperatures (e.g., 5000-15000 K).