  We report the electronic structure of methyne boron buckyballs B68(CH)12 and
B72(CH)8 obtained by substituting respectively 12 and 8 boron cap atoms by
methyne CH groups on the boron buckyball B80. DFT calculations and minimization
techniques have been employed to characterize the structural and electronic
properties of endo and exo isomers of these molecules in Th symmetry. A
vibrational frequencies analysis predicts that only endo-B72(CH)8 corresponds
to a true minimum on the potential energy hypersurface with a cohesive energy
similar to the boron buckyball. The viable existence of this carboron buckyball
opens new perspectives for a synthesis of large boron clusters.
