Theoretical re-investigation on the N–N bond breaking of N2O+ cations in the A2Σ+ and B2Π states at the CASPT2 level

•2D PESs along N–NO bond length and N–N–O bond angle of N2O+ in the A2Σ+ and B2Π states are calculated at the CASPT2 level.•Validated a novel adiabatic decomposition path of the A2Aʹ(A2Σ+) state in bent geometry to rotationally excited NO+(X1Σ+) and N(2D).•The respective contributions of the Aʹ and A″ components split from the B2Π state are clarified separately.