Langevin and molecular dynamics simulations of Lennard-Jones liquids

Simulations by Langevin dynamics technique are compared with molecular dynamics simulations. The potential of mean force and the self-diffusion coefficients at infinite dilution are obtained from suitable molecular dynamics simulations. A very simple case is studied: pure liquid krypton at three different thermodynamic states. Radial distribution functions obtained by both methods are in good agreement but marked discrepancies in time correlation functions and in self-diffusion coefficients are observed. These discrepancies may be attributed to hydrodynamic interactions and memory effects, which are ignored in our Langevin dynamics simulations.