An approximate solution of the FokkerPlanck equation for reactions in condensed phases
Abstract
The phase-space distribution function for reactive collisions in a condensed phase can be described by a Kramers-like FokkerPlanck equation. For the physical range of the relevant parameters we propose a realistic analytical approximation to the time-dependent distribution. The proposed solution can be motivated by physical consideration and/or by a variational principle and/or by the procedure of maximum entropy. A further useful approximation is to linearize the deterministic force about the mean trajectory. This limit which is not essential but very practical is similar to Heller's use of Gaussian wavepackets for the solution of the time-dependent Schrödinger equation.