A beyond Born-Oppenheimer treatment of five state molecular system [formula omitted] and the photodetachment spectra of its anion.

Graphical abstract Abstract A five-state multimode non-adiabatic dynamics has been performed on NO 3 by 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 NO 3 - to the doublet states ( X ∼ 2 A 2 ′ , A ∼ 2 E ″ and B ∼ 2 E ′ ) of NO 3 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 NO 3 - to simulate photodetachment spectra. The overall spectral profiles for 2 A 2 ′ and 2 E ″ states show reasonably good agreement with experimental results and that of 2 E ′ state with other theoretical calculations. [ABSTRACT FROM AUTHOR]