Reduction of the reflected pressure wave in the molecular-dynamics simulation of energetic particle-solid collisions

Abstract

The collision of an energetic, heavy particle with a solid generates a pressure wave. This leads to a difficulty in modeling the collision by molecular dynamics, as the wave is reflected at the boundary of the necessarily finite simulation zone, making any long-term prediction unreliable. A method has been developed that can drastically reduce the amplitude of the reflected wave. The impact region is described by a realistic potential that is embedded into a much larger harmonic system having the same elastic properties. The high-frequency response is corrected by an additional damping. Using this scheme the impact of an energetic copper cluster onto a copper surface was simulated. The final shape of the surface differed significantly from the outcome of the simulation using conventional Langevin molecular dynamics.