In this paper, we introduce a multi-scale nonequilibrium molecular dynamics (MS-NEMD) model that is capable of simulating nano-scale thermal–mechanical interactions. Recent simulation results using the MS-NEMD model are presented. The MS-NEMD simulation generalises the nonequilibrium molecular dynamics (NEMD) simulation to the setting of concurrent multi-scale simulation. This multi-scale framework is based on a novel concept of multi-scale canonical ensemble. Under this concept, each coarse scale finite element (FE) node acts as a thermostat, while the atoms associated with each node are assumed to be in a local equilibrium state within one coarse scale time step. The coarse scale mean field is solved by the FE method based on a coarse-grained thermodynamics model; whereas in the fine scale the NEMD simulation is driven by the random force that is regulated by the inhomogeneous continuum filed through a distributed Nośe–Hoover thermostat network. It is shown that the fine scale distribution function is canonical in the sense that it obeys a drifted local Boltzmann distribution.
Random Force in Molecular Dynamics with Electronic Friction
