The BEBO calculation of resonance energies of fullerene cages

A bond energy–bond order (BEBO) relationship for fullerene molecules was obtained by combining density functional theory (DFT) calculations with the Morse potential. The BEBO relationship provides a simple method to calculate the individual binding energies of all the C–C bonds of fullerenes. Consequently, one can easily calculate the resonance energies of the fullerenes using hypothetical compounds with non-resonant double bonds as reference states. This approach was applied to C60 and C70, both of which have about 3.9 kcal/mol of resonance energy per carbon.