A molecular dynamics study of doubly charged Ar2+n clusters

Molecular dynamics modeling of doubly charged Ar2+n cluster destruction is performed, where analytical expressions are constructed for the interatomic potentials. It is shown that for the small cluster Ar2+13, Coulomb explosion leads mostly to the detachment of ionic dimers. In larger clusters (n≥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 Ar2+n clusters’ stability is found to be nc=92–95, i.e., 92–95 atoms is the maximal size of a cluster undergoing Coulomb explosion.