First-principles calculations of clean Au(110) surfaces and chemisorption of atomic oxygen

Abstract

We present detailed density-functional theory studies of the structures of clean Au(110) surfaces and the energetics of various atomic oxygen coverages. Various $(1\ifmmode\times\else\texttimes\fi{}r)$ ``missing row'' reconstructions of the clean Au(110) surface have been investigated. The surface energies of the clean reconstructed surfaces are found to be very close with an energy minimum for $\text{Au}(110)\text{\ensuremath{-}}(1\ifmmode\times\else\texttimes\fi{}3)$. The (111) microfacets formed at $\text{Au}(110)\text{\ensuremath{-}}(1\ifmmode\times\else\texttimes\fi{}r)$ reconstructed surfaces with $r>1$ allow further adsorption sites. Adsorption in pseudothreefold-coordinated sites, along close-packed rows in the topmost gold layer, is favored over other adsorption sites. On $\text{Au}(110)\text{\ensuremath{-}}(1\ifmmode\times\else\texttimes\fi{}r)$, adsorption energies are generally higher for these sites.