New Stable and Fast Ring-Polymer Molecular Dynamics for Calculating Bimolecular Rate Coefficients with Example of OH + CH_4
arXiv:2205.09331 · doi:10.1021/acs.jctc.2c00522
Abstract
The accurate and efficient calculation of the rate coefficients of chemical reactions is a key issue in the research of chemical dynamics. In this work, by applying the dimension-free ultra-stable Cayley propagator, the thermal rate coefficients of a prototypic high dimensional chemical reaction OH + CH4 -> H2O + CH3 in the temperature range of 200 K to 1500 K are investigated with ring polymer molecular dynamics (RPMD), on a highly accurate full-dimensional potential energy surface. Kinetic isotope effects (KIEs) for three isotopologues of the title reaction are also studied. The results demonstrate excellent agreement with experimental data, even in the deep tunneling region. Especially, the Cayley propagator shows high calculation efficiency with little loss of accuracy. The present results confirmed the applicability of the RPMD method, particularly the speed-up by Cayley propagator, in theoretical calculations of bimolecular reaction rates.
arXiv comment35 pages, 7 figures (include one TOC),
References in corpus (7)
- Chemical Reaction Rates from Ring Polymer Molecular Dynamics: Theory and Practical Applications
- A simple and accurate algorithm for path integral molecular dynamics with the Langevin thermostat
- Cayley modification for strongly stable path-integral and ring-polymer molecular dynamics
- Dimension-free path-integral molecular dynamics without preconditioning
- A generalized class of strongly stable and dimension-free T-RPMD integrators
- Brush in the bath of active particles: anomalous stretching of chains and distribution of particles
- Rate coefficients of a roaming reaction H + MgH using the ring polymer molecular dynamics