Polyatomic radiative association by quasiclassical trajectory calculations: Cross section for the formation of HCN molecules in H + CN collisions

TL;DR

This paper extends classical radiative association theory to polyatomic molecules using quasiclassical trajectories, enabling calculation of cross sections for HCN formation in H + CN collisions.

Contribution

It introduces a polyatomic extension of a classical radiative association theory and a Monte Carlo scheme for quantum state-resolved cross sections.

Findings

Developed a global potential energy and dipole surface for H + CN.

Calculated and fitted cross sections for HCN formation.

Validated the polyatomic semiclassical method.

Abstract

We have developed the polyatomic extension of a recently established (M. Gustafsson, J. Chem. Phys, 138, 074308 (2013)) classical theory of radiative association in the absence of electronic transitions. The cross section of the process is calculated by a quasiclassical trajectory method combined with the classical Larmor formula which can provide the radiated power in collisions. We have also proposed a double-layered Monte Carlo scheme for efficient computation of ro-vibrationally quantum state resolved cross sections for radiative association. Besides the method development, we also calculated and fitted the global potential energy and dipole surface for the H + CN collisions to test our polyatomic semiclassical method.