Theoretical study of highly doped heterofullerenes evolved from the D _6h symmetry C₃₆ cage

The structural stabilities and electronic properties of singlet and triplet states C₂₄X₁₂ heterofullerenes where X = B, Al, C, Si, N, and P are probed at the B3LYP/6-31+G* level of theory. Vibrational frequency calculations show that all of the systems are true minima. The calculated binding energies of heterofullerenes show C₂₄B ₁₂ and C₂₄N₁₂ as the most stable heterofullerenes by 6.10 eV/atom and 5.63 eV/atom, respectively. While B, Al, N and P doping increase the conductivity of fullerene through decreasing its HOMO-LUMO gap, doping Si enhance its stability against electronic excitations via increasing the HOMO-LUMO gap. High charge transfer on the surfaces of our stable heterofullerenes, especially C₂₄Al₁₂ followed by C₂₄Si₁₂ and C₂₄P₁₂, provokes further investigations on their possible application for hydrogen storage.