Ring-polymer molecular dynamics study on rate coefficients of hydrogen abstraction of methane: A reduced-dimensional model

Abstract

To enhance computational efficiency of ring-polymer molecular dynamics (RPMD), reduced-dimensional models are proposed for X + YCZ3→ XY + CZ3. In these models, bond parameters of CZ3 are fixed keeping the C3v symmetry. These models are denoted by r-RPMD, t-RPMD, p-RPMD, i-RPMD, and irc-RPMD. Extensive RPMD calculations in both full- and reduced-dimensional fashions are performed for H + CH4. The computational efficiency of the reduced-dimensional calculation is found to be enhanced by a factor of roughly 3.5, which is close to 4 (factor for 12D → 3D). Good agreements between irc-RPMD and previous results are found.