Oblique Impacts and Rebounds of Lennard-Jones Clusters on Solid Surfaces

We report on molecular dynamics simulations of oblique impacts of Lennard-Jones clusters with a weakly attractive solid surface. We confirm that the probability of adhesion to the substrate by the cluster is largely determined by the normal velocity of the cluster. We also analyze the dependence of the angle of reflection on the impact velocity, showing that it can be understood in terms of the velocity dependence of Newton’s normal and tangential coefficients of restitution. In particular, we find that the tangential coefficient of restitution remains close to one, depending only weakly on the impact velocity, so that the angle of reflection is principally determined by the magnitude of the normal coefficient of restitution, which has a much stronger dependence on velocity. This strong velocity dependence means that at high velocities relatively small angles of reflection can occur.