Non-Equilibrium Molecular Dynamics and an Energy-Conserving Perturbation

We consider an implementation of non-equilibrium molecular-dynamics simulation with a new mechanical perturbation that conserves energy exactly. This eliminates completely the undesirable heating which always follows from standard mechanical perturbations. This method represents a simple direct approach to study transport properties without varying the system's total energy. As an application, the propagation dynamics of the perturbation are obtained with the subtraction technique for a three-dimensional Lennard-Jones solid model. The data indicate that the perturbation propagation has a velocity about typical of solid sound velocity.