Ordering of fractional monolayers of H₂O on Ni(110)

The ordering of water adsorbed on Ni(110) at monolayer and lower coverages was studied using molecular dynamics simulations. No long-range order could be found for the complete monolayer. At fractional coverage of θ ∼ 0.9, oriented zones of quasi-hexagonal ice-like structure are stabilized by the formation of empty gaps aligned along the 〈001〉 direction. At half coverage we observed the aggregation of hydrogen bonded patches. The growth process is dependent on the highly anistropic surface diffusion with the faster rate in the less dense 〈110〉 direction. These results have been obtained using a novel model for the water-substrate interaction, treating the site specific chemisorption and electrostatic induction in atomic detail.