The many faces of vibrational energy relaxation in N2(<i>v</i>) + O(1D) collisions: Dynamics on 1Π and 1Δ potential energy surfaces

Abstract

Complete datasets of rate coefficients for the vibrational quenching of molecular nitrogen by collision with electronically excited atomic oxygen O(1D) over a wide temperature range are calculated for the first time. Such data are important ingredients in the modeling of non-local thermal equilibrium conditions that characterize the atmosphere, media of astronomical interest, and cold and hot plasmas, where O(1D), also formed when O2 molecules break, represents a significant fraction of the gas mixture. To this end, we developed analytical potential energy surfaces (PESs) for the 1Π and 1Δ electronic states of the N2–O(1D) system to accurately describe the interaction in the long, medium, and first repulsive range of intermolecular distances, the most effective regions in inelastic collisions under a variety of conditions of interest. The derived PESs are used to calculate the vibration-to-translation (V–T) and vibration-to-electronic (V–E) energy transfer rates by mixed quantum–classical dynamics and by the Landau–Zener formulation, respectively. In addition, the datasets are extended to cover the entire N2 vibrational ladder by using the Gaussian process regression. The results show that at low temperatures, where V–E relaxation dominates, N2 vibrational quenching by O(1D) collisions is faster than by O(3P) collisions.