Ionization energies of multicharged fullerenes: Application and validity of an electrostatic model

A simple relation between the successive ionization energies of polycyclic aromatic hydrocarbons obtained in 1961 by Smith from a calculation of the work required to remove electrons in small particles, is extended here to the fullerene species Cnz+, n = 50-70, z = 1-5, and in some cases up to z = 8. Tests of the validity of the effective values of the parameters of the model, the work function and molecular capacitance, are given. The predicted ionization appearance energies are in excellent agreement with experimental values. A comparison is made between our model and other theoretical approaches to the calculation of the ionization energies of fullerenes.