Molecular dynamics simulations, via an empirical potential, have been performed in order to investigate geometries, growing patterns, structural stabilities, energetics, and magic sizes of copper clusters, Cu-n (n = 2-45). Possible optimal stable structures of the clusters have been generated through following rearrangement collision of the system in fusion regime. This process serves as an efficient alternative to the growing path identification and the optimization techniques. It has been found that copper clusters prefer to form three-dimensional compact structures in the determined configurations and the appearances of medium sizes are five fold symmetry on the spherical clusters. Moreover, relevant relations between atomic arrangements in the clusters and the magic sizes have been observed. Cu-26 may be accepted as another putative magic size like Cu-13.