Molecular dynamics simulation of gold cluster collisions

Abstract

Molecular dynamics (MD) simulation with an embedded atom method (EAM) potential is used to study gas-phase collisions of two 55-atom gold clusters. The probability of formation of a long-lived collision complex and the structure of this complex, after it is quenched to OK, are determined for head-on collisions in which each collision partner is chosen randomly from an equilibrium thermal bath. Two sets of collisions are studied. In the first the clusters are initially at OK, and in the second they are initially at 300K. All collisions result in cluster aggregation with significant inelastic deformation of the original clusters. The major conversion of potential energy into internal kinetic energy in the collision occurs on the time scale of a single vibrational oscillation. When the clusters are initially at OK, the collision complex is a solid cluster. When the clusters are initially at 300K, the collision complex is a liquid cluster.