COMPUTER-SIMULATION STUDY OF RELATIVE DIFFUSION IN SIMPLE LIQUIDS

Relative motions of particle pairs in a dense Lennard Jones liquid are investigated by molecular dynamics (MD) calculations. The relative velocities are split into their components parallel and perpendicular to the line of particles and the corresponding time correlation functions are calculated. The dependence of these correlation functions on the interparticle separation is discussed. Furthermore, the trajectories of a subset of particles of the same system are determined by generalized Langevin dynamics (GLD) simulation. The reliability of the atomic motion generated by the GLD method is verified by comparing the parallel and perpendicular relative velocity correlation functions resulting from GLD with those from MD.