On the behaviour of fluidic material at molecular dynamics boundary conditions used in hybrid molecular-continuum simulations

This paper presents an investigation of the behaviour of the density profile of fluidic material confined by a force field, as it occurs across molecular-continuum mechanics boundaries in multiscale, hybrid molecular-continuum simulations. A theoretical model for the density profile across the boundary is derived. Furthermore, numerical experiments to validate the density profile and thickness of the relaxation zone are performed using molecular dynamics for a Lennard-Jones fluid in gaseous, liquid and supercritical state conditions. The simulation results show excellent agreement with the theoretical model.