We calculated equilibrium structures for adsorption complexes of gold monomers, dimers, and trimers on a alpha-Al2O3(0001) model surface, partially covered by mu(1) and mu(3) hydroxyl groups. We applied a scalar-relativistic gradient-corrected density functional method to cluster models of the support that were embedded in an elastic polarizable environment. The most stable structures, with calculated adsorption energies in the range 0.81-1.74 eV, feature coordination bonds to surface mu(1)-OH group and are 0.24-0.79 eV more stable than the corresponding Au-n complexes on a dehydrated surface. Isomeric rearrangements of the most stable complexes are hindered by barriers of 0.65-1.08 eV. (C) 2010 Elsevier B. V. All rights reserved.