The electronic properties of the nonclassical four-membered ring fullerene (4-Me-C6H4)(2)-C-62, H-2-C-62, and F-2-C-62 are studied using the density functional theory. The computational results show that, the frontier orbitals of C-62, particularly the highest occupied molecular orbital, are localized mainly around the four-membered ring. High stability is predicted for (4-Me-C6H4)(2)-C-62 due to its much larger energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital, compared with that of C-62. The frontier orbitals theory is used to study the possibility of synthesizing H-2-C-62 and F-2-C-62 in which H-2 and F-2 are used to replace the (4-Me-C6H4)(2) in (4-Me-C6H4)(2)-C-62, and the results show that F-2-C-62 might be much stable and easier to synthesize than H2-C62, (c) 2006 Elsevier B.V. All rights reserved.