Molecular dynamics study of structural changes in freezing CuN (N=51-56) clusters

Structural changes of Cu-51-Cu-56 clusters during freezing have been studied by employing molecular dynamics(MD) simulations. With the growth of the crystallization phase, local patterns in different regions determined by the atom density profiles present different characteristic for these studied clusters. While the atom movements in the even-number clusters result in the formation of initial two-shell, then three-shell, and finally four-shell structures, the atoms in the odd-number clusters, with one exception of the Cu-51 cluster, first move into the central region and the outermost parts, then follow the movement from the inner parts into the outer parts. The crystallization temperature of these clusters has an oscillatory increase behavior for odd- and even- numbered copper atoms with increasing cluster size. (c) 2009 Elsevier Ltd. All rights reserved.