Charge-Induced Fragmentation of Sodium Clusters

The fission of highly charged sodium clusters with fissilities X>1 is studied by ab initio molecular dynamics. Na244+ is found to undergo predominantly sequential Na3+ emission on a time scale of 1ps, while Na24Q+ (5≤Q le 8) undergoes multifragmentation on a time scale ≥0.1 ps , with Na+ increasingly the dominant fragment as Q increases. All singly charged fragments Nan+ up to size n=6 are observed. The observed fragment spectrum is, within statistical error, independent of the temperature T of the parent cluster for T≤1500 K . These findings are consistent with and explain recent trends observed experimentally