C2 fragmentation energy of C60 revisited: theory disagrees with most experiments

Following our earlier work on the subject, we have carried out density functional theory (DFT) and second-order Møller–Plesset perturbation theory (MP2) calculations of the dissociation energy of the reaction C60→C58+C2 using polarized basis sets and geometries optimized with DFT methods. The present theoretical results support an electronic fragmentation energy De around 10–11 eV in disagreement with most experimental results that place the dissociation energy D0 (including zero point energy) around 7–8 eV. The plausible errors remaining in the theoretical calculations are unlikely to account for this big difference (2–4 eV).