Quantum‐mechanical reaction rate constants from centroid molecular dynamics simulations: Barrier crossing in an asymmetrical double‐well

Abstract

AbstractQuantum‐mechanical reaction rate constants were calculated from centroid molecular dynamics (CMD) simulations, for the case of barrier crossing in an asymmetrical double‐well potential bilinearly coupled to a harmonic bath. The calculation is based on a recently proposed formulation of the reaction rate constant in terms of the position—flux correlation function, which can be approximated via CMD in a well‐defined manner. The predictions of CMD and various simplified versions of it are compared to exact results, which were obtained via the quasi‐adiabatic propagator path integral (QUAPI) method, and/or path integral quantum transition state theory (PI‐QTST). The predictions based on CMD are found to be in good agreement with both.