Structure and Dynamics of Surface Adsorbed Clusters

Extensive numerical simulation are reported for the structure and dynamics of large clusters on metal(100) surfaces. Different types of perimeter hopping processes makes center-of-mass of the cluster to follow a a random walk trajectory. Then, a {\it diffusion coefficient} $D$ can be defined as $\lim\limits_{t\to \infty} D(t)$, with $D(t)=< d^2 >/(4t)$ and $d$ the displacement of the center-of-mass. In the simulations, the dependence of the diffusion coefficient on those perimeter hopping processes can be analyzed in detail, since the relations between different rates for the processes are explicitly considered as parameters.