title: Bonding mechanism and atomic geometry of an ordered hydroxyl overlayer on Pt(111).
abstract: Exposing water to a (2 x 2)-O precovered Pt(111) surface at 100 K and subsequently annealing at 155 K led to the formation of a well-ordered (square root 3 x square root 3)R30 degrees overlayer. The structure of this overlayer is determined by DFT and full dynamical LEED calculations. There are two O containing groups per (square root 3 x square root 3)R30 degrees unit cell and both occupy near on-top positions with a Pt-O bond length of (2.11 +/- 0.04) A. DFT calculations determined the hydrogen positions of the OH species and clearly indicate hydrogen bonds between the neighboring adsorbed OH groups whose interaction is mainly of electrostatic nature. A theoretical comparison with H(2)O shows the hybridization of OH on Pt(111) to be sp(3).
authors.affiliation: Contribution from the Department of Physical Chemistry, Fritz-Haber-Institut der MPG, Faradayweg 4-6, D-14195 Berlin, Germany.
authors.forename: A P
authors.initials: AP
authors.lastname: Seitsonen
authors.forename: Y
authors.initials: Y
authors.lastname: Zhu
authors.forename: K
authors.initials: K
authors.lastname: Bedürftig
authors.forename: H
authors.initials: H
authors.lastname: Over