Excited nano-clusters

We discuss structural and dynamical properties of nano-clusters consisting of krypton and aluminum. The investigations are based on molecular dynamics calculations. In this way anharmonic effects could be fully considered. The dynamics has been studied by means of the generalized phonon density of states and the mean-square displacements as a function of time. In order to investigate the structure of the clusters, we have also calculated the structure factor S(q). The calculations have been done for a few hundred atoms and for various temperatures. In the case of Al not only stable cluster states could be identified but also clusters in a metastable state. The clusters in the metastable state show a well-defined peak in the structure factor S(q) which we interpret as superstructure. The appearance of the superstructure in the metastable state is accompanied by substantial changes in the phonon density of states.