Ro-vibronic spectrum of the N2O+ ion in the X 2Π state

Abstract

Three-dimensional potential energy functions (PEFs) for the two components of the electronic ground state X 2Π state of the N2O+ radical cation have been calculated using multi-configuration self-consistent field approach. The theoretical PEFs and the existing experimental information have been combined to generate empirical PEFs for the beyond Born-Oppenheimer variational calculations of the ro-vibronic energy levels including the couplings of the rotation-vibration, the electron spin and the electronic angular momenta. Band origins (J = P) are given for energies up to 4500 cm−1. The experimentally known vibronic energy levels are reproduced with an accuracy of better than 5 cm−1 for the vibronic states with K ⩽ 2. The anharmonic coupling effects have been investigated.