A State-Space-View of Atom-Diatom Reactions Relevant to Rarefied Gas Flow

TL;DR

This paper uses quasi-classical trajectories on detailed potential energy surfaces to map energy flow and reaction outcomes in atom-diatom collisions, aiding the understanding of non-equilibrium chemistry in hypersonic and rarefied gases.

Contribution

It introduces a comprehensive state-space approach to analyze energy redistribution and reaction dynamics in atom-diatom collisions using multiple potential energy surfaces.

Findings

Distinct structure-reactivity relationships identified.

Consistent trends across different potential energy surfaces.

Provides a basis for improved non-equilibrium chemistry modeling.

Abstract

A microscopically resolved picture of energy flow in atom-diatom collisions is essential for understanding the non-equilibrium chemistry in rarefied and hypersonic gas flow. Here, a comprehensive ensemble of quasi-classical trajectories on global, reactive, and ``vetted'' potential energy surfaces are employed to construct state-resolved probability maps and to determine the dependence of the outcomes on the initial ro-vibrational states $(v,j)$. The full range of processes, including elastic, inelastic, atom exchange, reactive, and atomization are quantified, revealing distinct structure reactivity relationships. For the [OOO] system consistent trends are obtained from two high-quality potential energy surfaces, despite their different electronic structure and representation techniques. The resulting state-space description provides a comprehensive picture of energy redistribution in high-energy atom-diatom collisions, forming a basis for improved modeling of non-equilibrium chemistry in hypersonic and rarefied environments.