Adsorption and diffusion of an Au atom and dimer on a θ-Al2O3 (001) surface

► We perform DFT calculations to study adsorption and diffusion of an Au atom and dimer on a θ-Al2O3(001) surface. ► The θ-Al2O3(001) surface has an armchair-like configuration containing flat and trench areas. ► The adsorption energies and configurations of the small Au clusters are determined. ► The small Au clusters diffuse anisotropically on the θ-Al2O3(001) surface.