The adsorption of H-2 on a series of 3d transition-metal (TM)-doped organosilica complexes is investigated using density functional calculations. We show that a modified benzene-silica (MBS) model with the 3d TM atoms can adsorb H-2 as dihydride or dihydrogen configurations except the model with Fe, Co, or Ni, which can store hydrogen as dihydrogen forms only. The maximum numbers of H-2 molecules adsorbed are one to three for the various TM atoms, with the average binding energies of 0.4-0.9 eV. We propose that the TM-MBS (TM = Sc, Ti, and V) complexes can be the building blocks in designing hydrogen storage materials. (C) 2010 Elsevier B. V. All rights reserved.