Simulation of the photodetachment spectra of the nitrate anion (NO) in the B̃ E' energy range and non-adiabatic electronic population dynamics of NO.

The photodetachment spectrum of the nitrate anion (NO) in the energy range of the NO second excited state is simulated from first principles using quantum wave packet dynamics. The prediction at 10 K and 435 K relies on the use of an accurate full-dimensional fully coupled five state diabatic potential model utilizing an artificial neural network. The ability of this model to reproduce experimental spectra was demonstrated recently for the lower energy range [A. Viel, D. M. G. Williams and W. Eisfeld, 2021, , 084302]. Analysis of the spectra indicates a weaker Jahn-Teller coupling compared to the first excited state. The detailed non-adiabatic dynamics is studied by computing the population dynamics. An ultra-fast non-statistical radiationless decay is found only among the Jahn-Teller components, which is followed by a slow statistical non-radiative decay among the different state manifolds. The latter is reproduced perfectly by a simple first order kinetics model. The dynamics in the second excited state is not affected by the presence of a conical intersection with the first excited state manifold.