A transition state resonance radically reshapes angular distributions of the F + H2 -> F H(vf = 3) + H reaction in the 62-101 meV energy range

TL;DR

This study reveals that a transition state resonance significantly influences the angular distribution in the F + H2 reaction at energies between 62-101 meV, explaining unusual scattering patterns observed experimentally.

Contribution

The paper introduces a novel application of Regge trajectories and complex energy poles to quantify the impact of a known transition state resonance on reaction angular distributions.

Findings

Resonance causes small-angle scattering propensity.

Transition state resonance dominates the angular distribution.

Application of DCS Regge package enables detailed analysis.

Abstract

Reactive angular distributions of the benchmark F + H2(vi = 0) -> F H(vf = 3) + H reaction show unusual propensity towards small scattering angles, a subject of a long debate in the literature. We use Regge trajectories to quantify the resonance contributions to state-to-state differential cross sections. Conversion to complex energy poles allows us to attribute the effect almost exclusively to a transition state resonance, long known to exist in the F +H2 system and its isotopic variant F +HD. For our detailed analysis of angular scattering we employ the package DCS Regge, recently developed for the purpose [Comp. Phys. Comm., 2022, 277, 108370.]