Quantum calculations of the photoelectron spectra of the OH·NH anion: implications for OH + NH → HO + NH reaction dynamics

We present the results of quantum dynamics calculations for analyzing the experimentally measured photoelectron spectra of the OH − ·NH 3 anion complex. Detachment of an excess electron of OH − ·NH 3 initially produces a molecular arrangement, which is close to the transition-state structure of the neutral OH + NH 3 → H 2 O + NH 2 hydrogen abstraction reaction due to the Franck-Condon principle, and thus finally leads to the OH + NH 3 or H 2 O + NH 2 asymptotic channel. We used both the path integral method and the reduced-dimensionality quantum wave packet method to simulate the photoelectron spectra of the OH − ·NH 3 anion. The calculated spectra were found to be in qualitative agreement with the experimental spectra. It was found that the photodetached complex mainly dissociates into the OH + NH 3 channel; however, we found that the hydrogen exchange process also contributes to the photodetachment spectra. Quantum dynamics calculations were performed to analyze the experimentally measured photoelectron spectrum of the OH − ·NH 3 anion complex.