MOLECULAR-DYNAMICS SIMULATION OF GOLD CLUSTER COLLISIONS

Molecular dynamics (MD) simulation with an embedded atom method (EAM) potential is used to study gas-phase collisions of two 55-atom gold cl usters. The probability of formation of a long-lived collision complex and the structure of this complex, after it is quenched to OK, are de termined for head-on collisions in which each collision partner is cho sen 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 a ggregation with significant inelastic deformation of the original clus ters. The major conversion of potential energy into internal kinetic e nergy in the collision occurs on the time scale of a single vibrationa l oscillation. When the clusters are initially at OK, the collision co mplex is a solid cluster. When the clusters are initially at 300K, the collision complex is a liquid cluster.