The adsorption of methanol on the (1:1) nickel/aluminum (100) surface is modeled by quantum mechanical calculations on a small cluster, using hybrid Hartree-Fock/density functional theory. The enthalpy of adsorption at the limit of zero coverage is calculated for the high-symmetry sites. The importance of tipping of the prevalent methoxy radical species to C-O bond scission is examined. A new mechanism for dissociation is proposed, which is in excellent agreement with experimental determinations of the energy of activation for dissociation. Comparisons are made to similar reactions on Al (100). (C) 2000 Academic Press.