Size limits and fission channels of doubly charged noble gas clusters.

Small, highly charged liquid droplets are unstable with respect to spontaneous charge separation when their size drops below the Rayleigh limit or, in other words, their fissility parameter exceeds the value 1. The absence of small doubly charged atomic cluster ions in mass spectra below an element-specific appearance size has sometimes been attributed to the onset of barrierless fission at = 1. However, more realistic models suggest that marks the size below which the rate of fission surpasses that of competing dissociative channels, and the Rayleigh limit of doubly charged van der Waals clusters has remained unchartered.

Doubly charged dimers and trimers of heavy noble gases.

Many doubly charged heteronuclear dimers are metastable or even thermodynamically stable with respect to charge separation. Homonuclear dicationic dimers, however, are more difficult to form. He was the first noble gas dimer predicted to be metastable and, decades later, observed.