BONDING AND ELECTRONIC-PROPERTIES OF SUBSTITUTED FULLERENES C58B2 ANDC58N2

The binding energies and electronic properties of substituted fulleren es C58B2 and C58N2 have been calculated. by a self-consistent-field mo lecular-orbital (MO) method; their structures are optimized by a MO me thod with Harris-functional and spin-restricted approximations. The mo st striking change by multiple substitutions is that the binding energ ies (5.90 and 5.92 eV/atom) of C58N2 isomers are much smaller than tha t (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-occup ied MO and the lowest-unoccupied MO are also changed by multiple subst itutions, being 0.49 and 0.54 eV (C58B2 isomers), 0.23 and 0.28 eV (C5 8N2 isomers), and these sizes are much smaller than that (1.50 eV) of C60.