Correcting Rate Constants from Anharmonic Molecular Dynamics for Quantum Effects.

ABSTRACT: Anharmonicity can greatly affect rate constants. One or even several orders of magnitude of deviation are found for obtaining rate constants using the standard rigid-rotor harmonic-oscillator model. In turn, reactive molecular dynamics (MD) simulations are a powerful way to explore chemical reaction networks and calculate rate constants from the fully anharmonic potential energy surface. However, the classical nature of the dynamics and the required numerical efficiency of the force field limit the accuracy of the resulting kinetics. We combine the best of both worlds by presenting an approximation that pairs anharmonic information intrinsic to classical MD with high-accuracy energies and frequencies from quantum-mechanical electronic structure calculations. The proposed scheme is applied

SUBMITTER: Schmalz F 

PROVIDER: S-EPMC7016917 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature