The HF(v'=3) forward scattering peak of the F + H2 reaction revisited

TL;DR

This study uses quantum mechanical calculations to analyze the forward scattering peak of HF(v'=3) in the F + H2 reaction, revealing it results from energy constraints and rotational effects at specific vibrational levels.

Contribution

It revisits the HF(v'=3) forward scattering peak with detailed quantum calculations, clarifying its origin from combined vibrational and rotational dynamics.

Findings

HF(v'=3) forward scattering peak caused by energy constraints and rotational effects

The peak's intensity increases with higher vibrational levels v'

Absence of high j' products at v'=3 due to energy limitations

Abstract

A quantum mechanical coupled-channel scattering calculation on the Stark-Werner potential energy surface is used to study the F + H2(v=0; j=0,1,2) ---> H + HF(v', j') reaction at collision energies of 1.84, 2.74, and 3.42 kcal/mol. The dependence of the vibrationally and rotationally resolved differential cross sections on the product vibrational levels v'=0, 1, 2, and 3 as well as on the reactant and product rotational levels is analyzed. The HF(v'=3) center-of-mass forward scattering peak is shown to be caused by the superposition of two effects, namely, the absence of the HF(v'=3; j') products with large j' values due to energy constraints and the growth of the rotationally resolved HF(v', j') forward scattering peak with small j' values as v' increases.