The diffusion of passing over the saddle point of a three-dimensional quadric potential energy surface was studied by analytically solving a set of coupled generalized Langevin equations. An accurate expression of the passing probability was obtained. The effect of the coupling between different degrees of freedom which is represented by the off diagonal elements of the inertia, friction and potential-curvature tensors was analyzed in detail. It is found that some of the coupling have great influence on the diffusion process, while others not. The combination of them results in an optimal injecting direction of the diffusing particles, revealing an optimal three-dimensional diffusion path. (C) 2021 Elsevier B.V. All rights reserved.
Key words
Diffusion/Three-dimensional/Langevin equation/Passing probability/TRANSITION-STATE THEORY/KRAMERS FORMULA
NSTL
Elsevier