The self-diffusion coefficients were calculated in a model of a planar interface between two almost immiscible liquids. The simulations were performed by the molecular dynamics method, using Lennard-Jones potentials. The diffusion process was isotropic in the bulk regions of the simulated system, whereas it exhibited anisotropic behaviour in the interfacial region: the transverse diffusion coefficient (parallel to the interface) was higher than the normal one. A qualitative explanation of this behaviour was suggested by comparison with the pressure tensor.

Molecular Dynamics Study of Self-Diffusion in a Liquid-Liquid Interface. Hayoun, M., Meyer, M., Turq, P.: Chemical Physics Letters, 1988, 147[2-3], 203-7