A MOLECULAR-DYNAMICS STUDY OF DOUBLY-CHARGED AR-N(2+) CLUSTERS

Molecular dynamics modeling of doubly charged Ar-n(2+) cluster destruction is performed, where analytical expressions are constructed for the interatomic potentials. It is shown that for the small cluster Ar-13(2+), Coulomb explosion leads mostly to the detachment of ionic dimers. In larger clusters (n greater than or equal to 55), Coulomb explosion leads to the fission of the doubly charged cluster to two singly charged clusters of similar size. After the fission, the singly charged clusters evaporate some number of neutral atoms. The critical size of the Ar-n(2+) clusters' stability is found to be n(c)=92-95, i.e., 92-95 atoms is the maximal size of a cluster undergoing Coulomb explosion.