@article {53, title = {Theoretical study of passivated small fullerenes C24-X4 (X = N, P, As) and theirisoelectronic equivalents (BN)12-X4}, journal = {Chem.Phys. Lett.}, volume = {255}, year = {1994}, pages = {448}, author = {E. Kaxiras and K. Jackson and M.R. Pederson} }