title: Monomer structures of water adsorbed on p(2 x 2)-Ni(111)-O surface at 25 and 140 K studied by surface X-ray diffraction.
abstract: The structures of a monomeric water molecule adsorbed on p(2 x 2)-Ni(111)-O surface were determined by difference Fourier calculations. At temperatures of 25 K, water molecules chemisorb predominantly at 2 x 2 oxygen atom sites, forming an OH---O(ad) (2 x 2) hydrogen bond. A 2 x 2 oxygen atom (O(ad)) is surrounded by one to three monomeric water molecules, which take statistically disordered positions with threefold symmetry. At temperatures of 140 K, monomeric water molecules occupy a top site of Ni atoms via an oxygen lone pair and are stabilized as a singleton molecule on the surface.
authors.affiliation: Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Chiba University, Inage-ku, Chiba 263-8522, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Nakamura
authors.forename: Masatoki
authors.initials: M
authors.lastname: Ito