electronic properties of hydrogen adsorption on the silicon- substituted c20 fullerenes: a density functional theory calculations

the b3lyp/6-31++g** density functional calculations were used to obtain minimum geometries and interaction energies between the molecular hydrogen and nanostructures of fullerenes, c20 (cage), c20 (bowl), c19si (bowl, penta), c19si (bowl, hexa). the h2 molecule is set as adsorbed in the distance of 3å at vertical position from surface above the pentagonal and hexagonal sites of nanostructures. by comparing of gap energies, electronic chemical potential, hardness and results of qtaim (quantum  theory of atom in molecules) analysis, the si atom substitution in hexa two- fold position of c20 (bowl)may be suitable for the adsorption of hydrogen molecule.