Investigation of nonadiabatic coupling and diabatic electronic population dynamics on F₂O⁺ cation within multi reference configuration interaction calculations

Abstract

In F2O+ cation the first (2B2) and second excited (2A1) electronic states can be coupled with each other by anti‐symmetric stretching mode and thus conical intersection and non‐adiabatic dynamics play an important role in characterizing molecular properties. In this work, we tried to find a suitable computational method for determining equilibrium structures and harmonic vibrational frequencies of the three lowest electronic states of F2O+. To understand non‐adiabatic dynamics at conical intersections, we calculated the probability of electronic population on 2B2 and 2A1 excited electronic states using linear vibronic coupling Hamiltonian mode including all three vibrational modes (bending (ω1), symmetric stretching (ω2) and anti‐symmetric stretching (ω3)).The amount of vibronic coupling constant between these states is obtained 0.08 eV at multi reference configuration interaction/Aug‐cc‐pVQZ level of theory.