title: Effect of subsurface Ti-interstitials on the bonding of small gold clusters on rutile TiO(2)(110).
abstract: The density functional theory is used to examine the electronic structure of small Au clusters, supported on rutile TiO(2)(110) surfaces having subsurface Ti-interstitials. The interstitials reduce the surface and we find that negatively charged gold clusters are stabilized with respect to the stoichiometric surface. The behavior of the open-shell gold clusters can be rationalized in terms of the highest occupied molecular orbitals and the resulting electron affinities. The relative stabilities of closed-shell gold clusters led to recent disagreements in the literature. We show that they are very dependent on the density functional used. As expected, a redshift in the CO stretch vibration is calculated for CO adsorbed on a negatively charged cluster. Somewhat surprisingly a larger redshift is found for CO adsorbed on an overall positively charged Au(3) cluster. This is explained by CO being a local probe of the individual Au charges and one Au atom having an electron accumulation.
authors.affiliation: Department of Physics and Astronomy and Interdisciplinary Nanoscience Center (iNANO), University of Aarhus, DK-8000 Aarhus C, Denmark.
authors.forename: Georg K H
authors.initials: GK
authors.lastname: Madsen
authors.forename: Bjørk
authors.initials: B
authors.lastname: Hammer
mesh_terms: D002248:Carbon Monoxide / Q000737:chemistry; D016000:Cluster Analysis; D006046:Gold / Q000737:chemistry*; D008956:Models, Chemical; D011108:Polymers / Q000737:chemistry; D055672:Static Electricity; D014025:Titanium / Q000737:chemistry*
chemical_list: D011108:Polymers; C009495:titanium dioxide; D006046:Gold; D002248:Carbon Monoxide; D014025:Titanium