Molecular-dynamics study on the equilibrium structure and the stability of a cluster dimer

The equilibrium structures and the dynamic properties of two interacting clusters (cluster dimer), both of which have 13 atoms with icosahedral symmetry, have been studied by the molecular-dynamics method. A few metastable structures have been observed, but we obtain only one ground-state structure near the zero temperature for the various interaction strengths between two clusters, in which the icosahedral symmetry remains for each cluster. Upon heating, the ground structure for the cluster dimer is destroyed at a certain temperature (Formula presented), which is strongly dependent on the interaction strength. At a temperature higher than (Formula presented), one cluster loses the icosahedral symmetry and begins to cap onto the other cluster; and if heating further, both clusters begin to melt. The relationship between (Formula presented) and the interaction strength is also obtained.