We develop an inverse friction expansion for the diffusion of particles in an inhomogeneous medium based on the Mori formalism starting from a microscopic Hamiltonian. The friction is related to the vibrational correlation function of the substrate. An analytic formula is obtained for the diffusion constant in the high-friction limit.

• Received 25 August 1989

DOI:https://doi.org/10.1103/PhysRevB.41.7068