Fragmentation Behavior and Ionization Potentials of Lead Clusters Pb-n(n <= 30)

The properties of Pb-n(n=2-30) clusters including binding energies, second differences in energy, and HOMO-LUMO gaps, especially fragmentation energies and ionization potentials, have been studied by ab initio calculation. The main fragmentation products of Pb-n(+) are shown to be Pb+Pb-n-1(+) for n <= 14 and two small cluster fragments for larger ones with n>14. The Pb-13(+) appears frequently as the products in the fragmentations of large clusters. Also, the calculated ionization potentials of the clusters are consistent with the experiment data.