Langevin equation in momentum space

摘要

The generalized Langevin equation encapsulates in the friction kernel the influence of the environment on the reaction coordinate.We have decomposed the Langevin equation in a Fourier transform representation and analyzed how different Fourier components contribute to the friction krnel.We identified that a long-wavelength contriburtion to the friction kernel originates from collective solvent motions,and we compared it with contributions coming from short-range scattering of the complex with the surrounding solvent atoms.