Ionization potentials and dissociation energies of neutral, singly and doubly charged Cn fullerenes from n = 20 to 70

Using B3LYP density functional theory, first and second ionization potentials as well as dissociation energies for neutral, singly and doubly charged fullerenes with sizes between 20 and 70 atoms have been evaluated. Comparison with available experimental data is good except for the doubly charged species. The results show that neutral fullerenes with a magic number of atoms, namely C32, C50, C60 and C70, have the largest stability against ionization and C2 evaporation. A similar large stability is observed for the corresponding singly and doubly charged magic fullerenes, except for C32+ and C322+. Neutral and positively charged C62 is found to be rather unstable. Also, C2+ emission is shown to become competitive with C2 emission for sufficiently small doubly charged fullerenes. The origin of these and other properties is discussed in detail.