Effects of multimode Jahn-Teller coupling on the photodetachment spectrum of nitrate anion ()

The multimode static and dynamic Jahn-Teller effects in the 2E″ and 2E′ excited states of the nitrate radical (NO3) and their impact on the vibronic structure of the photodetachment spectrum of the nitrate anion are investigated theoretically. The analysis rests on the quadratic vibronic coupling approach and large-scale multi-reference configuration interaction calculations for the determination of the respective coupling parameters. The possible pseudo-Jahn-Teller interactions between the ground 2 A 2 ′ and excited 2E′ electronic states of NO3 are also included in the vibronic coupling model. The results of the 2E″ state are compared with the experimental recording of Neumark and co-workers, while those for the 2E′ state come as a prediction. The deviations between theoretical and experimental vibronic structures of the 2E″ photoelectron band are discussed.