AB-INITIO ELECTRONIC-STRUCTURE CALCULATIONS ON HIGHLY-CHARGED CATIONSOF THE C-60 CLUSTER

Ab initio electronic structure calculations on C-60 and its cations, c arried out at the HF/6-311G level of approximation, predict that with in I-h symmetry the C-60(10+), C-60(18+), and C-60(28+) species are st able with respect to fragmentation. The bonds in these cations lengthe n with the increasing positive charge. The lengthening is more pronoun ced for the bonds connecting the five-membered rings than for those wi thin the rings. The C-60 cluster is capable of losing more than 28 ele ctrons, absorbing at least 1379 eV of energy in the process, before un dergoing a highly symmetrical fragmentation. Such a fragmentation is p redicted to involve preferential breaking of the ''double'' bonds, lea ding to positively charged C-5 fragments.