Rate Constants of the H + HCF3 → H2 + CF3 Reaction from Ring Polymer Molecular Dynamics on a Highly Accurate Potential Energy Surface.

Abstract

The reaction between H and HCF₃ is the primary consumption pathway of HCF₃ in the atmosphere and combustion. In this work, ring polymer molecular dynamics (RPMD) calculations are performed to calculate the rate constants of the reaction on a recently developed accurate potential energy surface. 36, 20, and 8 beads are used to compute the rate constants at 350 K ≤ T < 800 K, 800 K ≤ T ≤ 1000 K, and T > 1000 K, respectively. The obtained RPMD rate constants agree well with the experimental measurements. In addition, a detailed analysis of the free-energy curves and transmission coefficients reveals that the quantum tunneling significantly affects the reaction dynamics, even at high temperatures.