A beyond Born-Oppenheimer treatment of five state molecular system NO₃ and the photodetachment spectra of its anion

Abstract

A five-state multimode non-adiabatic dynamics has been performed on NO₃by constructing accurate diabatic potential energy surfaces (PESs) in vibronically coupled manifold using beyond Born-Oppenheimer (BBO) theory. In this article, we have considered the photodetachment of NO₃^-to the doublet states (X̂² A'₂, ² E" and B̂²E') of NO₃ and determined the vibronic couplings and conical intersections of the latter. Using ab initio calculated adiabatic PESs and Non-adiabatic Coupling Terms, we have carried out adiabatic-to-diabatic transformation (ADT) in five-state sub-Hilbert space to obtain ADT angles and thereby, constructed single-valued, smooth, symmetric and continuous diabatic PESs. The explicit analytic expressions for diabatic PESs and coupling elements are provided. Subsequently, we have performed nuclear dynamics starting from the electronic ground state of NO₃^- to simulate photodetachment spectra. The overall spectral profiles for ²A'₂ and ²E" states show reasonably good agreement with experimental results and that of ²E' state with other theoretical calculations.