Ab initio potential energy surfaces for excited states of the NO2+ molecular ion and for the reaction of N+ with O2

Abstract

Multi-reference configuration interaction calculations are presented for excited states of the NO2+ molecular ion. Bending potential energy curves are calculated for a number of low-lying states and dissociation to [NO+O]+ is considered for linear geometries and for a bond angle of 120°. The very fast dissociation of the b̃ 3A2 state can be understood in terms of a very shallow quasi-bound minimum on the potential energy surface whereas the potential well for the ã 3B2 state is considerably deeper. Potential energy curves relevant to the reaction N+(3P)+O2(X 3Σg−) are calculated. It is suggested that the reaction proceeds via a nonadiabatic transition in the entrance channel from the 2 1Σ+ surface to the 1 1Σ+ surface which correlates adiabatically with O(1D)+NO+(X 1Σ+). The observation of O(3P)+NO+(X 1Σ+) as a minor channel is interpreted in terms of a nonadiabatic transition, mediated by spin-orbit coupling, from the 1 1Σ+ surface to the 1 3Π surface in the exit channel.