BONDING AND ELECTRONIC-PROPERTIES OF SUBSTITUTED FULLERENES C58B2 AND C58N2

The binding energies and electronic properties of substituted fullerenes C58B2 and C58N2 have been calculated. by a self-consistent-field molecular-orbital (MO) method; their structures are optimized by a MO method with Harris-functional and spin-restricted approximations. The most striking change by multiple substitutions is that the binding energies (5.90 and 5.92 eV/atom) of C58N2 isomers are much smaller than that (6.05 eV/atom) of C60, while those (6.01 and 6.03 eV/atom) of C58B2 isomers are almost the same. The energy gaps between the highest-occupied MO and the lowest-unoccupied MO are also changed by multiple substitutions, being 0.49 and 0.54 eV (C58B2 isomers), 0.23 and 0.28 eV (C58N2 isomers), and these sizes are much smaller than that (1.50 eV) of C60.