The density functional theory was used to examine the electronic structure of small

Au clusters, supported on rutile TiO2(110) surfaces having subsurface Tiinterstitials.

The interstitials reduce the surface and it was found that negatively

charged gold clusters were stabilized with respect to the stoichiometric surface.

The behaviour 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. It was shown that they were very dependent on the density functional

used. As expected, a redshift in the CO stretch vibration was calculated for CO

adsorbed on a negatively charged cluster. Somewhat surprisingly a larger redshift was found for CO adsorbed on an overall positively charged Au3 cluster. This was

explained by CO being a local probe of the individual Au charges and one Au atom

having an electron accumulation.

Effect of Subsurface Ti-Interstitials on the Bonding of Small Gold Clusters on

Rutile TiO2(110). G.K.H.Madsen, B.Hammer: Journal of Chemical Physics, 2009,

130[4], 044704