Rydberg states and new resonant states of the imidogen molecule NH: pathways for nitrogen release

TL;DR

This study uses detailed R-matrix calculations to identify and characterize bound and resonant states of the imidogen molecule NH across various internuclear distances, providing new data for understanding its dissociation dynamics.

Contribution

It presents the first comprehensive analysis of NH resonant states over multiple geometries, including many states not previously studied, and calculates their widths systematically.

Findings

Identified numerous new resonant states of NH.

Calculated widths for these resonant states.

Provided detailed potential energy curves for NH.

Abstract

Neutral resonant states of molecules play a very important role in the dissociation dynamics and other electronic processes that occur via intermediate capture into these states. With the goal of identifying resonant states, and their corresponding widths, of the imidogen molecule NH as a function of internuclear distance, we have performed detailed R-matrix calculations on the e + NH+ system. In a previous work, we had identified bound states of NH and Feshbach resonances in the e + NH+ system at a single geometry, namely the NH+ equilibrium Re = 2.0205 a0 . Here we present a much more detailed work by repeating the calculation on over 60 internuclear distances to obtain the corresponding potential energy curves. The bound states for nine symmetries have been detailed many of which, particularly the singlet states, were never studied before. Several resonant states of different symmetries, which were unknown until now, have been systematically identified and their widths calculated in the present work, which proved much more challenging due to presence of many avoided crossings. It is hoped that the bound and the new resonant states obtained here will open up other molecular dynamics studies, since for several dissociative processes, although experimental data existed for more than a decade, these are still uncorroborated due to absence of molecular data, and hence subsequent theoretical calculations.