We report results of full geometry optimization and harmonic vibrational frequencies of the minimum energy structure of C48B12, and two low-lying isomers at the B3LYP/6-31G* level of theory. The minimum energy structure of C48B12 proved to be the same as we have found in the case of C48N12 [J. Am. Chem. Soc. 124 (2002) 13990]. The two low-lying structures with D-3d and S-6 symmetry proved to be 15 and 26 kcal/mol energetically less stable, respectively. Mulliken charge analysis showed that the minimum energy structure of C48B12 could serve as an electron acceptor, in contrast to the donor character Of C48N12. (C) 2003 Published by Elsevier B.V.