Extensive numerical simulation are reported for the structure and dynamics of large clusters oil metal (100) surfaces, Different types of perimeter hopping processes makes center-of-mass of the cluster to follow a random walk trajectory. A diffusion coefficient 1) for the whole cluster can be defined as lim(t ->similar to) D(t), with D(t) = < d(2)>/(4t) and d the displacement of the center-of-mass from its initial position. 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. (c) 2005 Elsevier B.V. All rights reserved.