Theoretical study of ionization potentials and dissociation energies of Cnq+ fullerenes (n=50-60, q=0, 1 and 2)

We have evaluated electronic energies of neutral, singly charged and doubly charged fullerenes with sizes n=50-60 using density functional (DFT) theory. For each value of the cluster charge, we have considered around 40 possible structures. We have found that, except for C-52(2+), the most stable isomer always has the minimum possible number of C-2 units between adjacent pentagons. We have evaluated adiabatic dissociation energies corresponding to the various dissociation channels leading to the emission of carbon dimers with different charges. Our findings for dissociation leading to C-2 emission are in reasonable agreement with the latest experimental values. As a byproduct of our calculations, we have also evaluated the first and second adiabatic ionization potentials. Both dissociation energies and ionization potential are useful data to interpret fragmentation of fullerenes by impact of energetic photons, electrons and ions. (C) 2003 American Institute of Physics.