Vibrational properties of C60: A comparison among different inter-atomic potentials

Using seven bond-order potentials and five force fields, the fundamental natural frequency of C60,Ag(1) (breathing mode), and two other basic modes, namely Hg(1) (squashing mode) and T2g(1) are calculated. The same frequencies are derived through a DFT B3LYP/6-31G(d) calculation. Furthermore, the results are compared with Raman and IR scattering data, and previous quantum mechanics calculations, depicting the strength of each interatomic potential in predicting the vibrational properties of Buckminsterfullerene. AIREBO, which is formulated for analyzing hydrocarbons, shows the highest accuracy among all of the potentials under investigation. In general, bond-order potentials predict a flexible structure for the molecule with smaller frequencies and a large radius. On the other hand, force fields tend to attribute a larger stiffness and smaller size to the whole structure.