METASTABLE DECAY OF RARE-GAS CLUSTER IONS - THE (AR3)+ SYSTEM

The decay of (Ar3+)* --> Ar2+ + Ar is studied from a dynamical viewpoint by employing an effective, spherical interaction and constructing the complete set of bound and metastable wavefunctions for the full range of rotational states of the triatomic complex. In agreement with the experimental findings, the present calculations show that the effect of populating the high rotational states of the overall cluster gives rise to a wealth of new resonances (predissociative tunnelling) and can cover a very broad range of metastable dissociation rates, with lifetimes ranging from 10(-11) s to 10 s. Such a dynamical mechanism could therefore provide a simple explanation for the observed behaviour of rare gas cluster ions and could indicate further ways of improving the modelling of such processes.