METASTABLE DECAY OF IONIC ARGON CLUSTERS - ROTATIONAL PREDISSOCIATIONOF (AR)(4)(+)

A fully anisotropic potential energy surface (PES) is constructed for the ground electronic state of the (Ar)(4)(+) system in order to analy se the interaction of the Ar-3(+) core with a residual argon atom. Usi ng the highly anisotropic PES found in this case, we carry out a detai led analysis of the consequences of energy storing in the rotational d egrees of freedom of the core on the quantum fragmentation of the full system. We find that such process provides a highly efficient break-u p channel until the overall rotational temperature of the cluster mana ges to block the lower levels of metastability into slow-decaying stat es of the full cluster. The effect of such findings on the general mod elling of cluster metastability is also analysed and discussed.