We present a detailed investigation of the $c(2\mathrm{}\times 2)-\mathrm{Br}/\mathrm{Pt}\mathrm{}\left(110\right)\mathrm{}$ adlayer structure supplemented by the analysis of the $(1\mathrm{}\times 2)$ missing-row (MR) structure of the clean Pt(110) surface. Quantitative low energy electron diffraction analyses and first-principles calculations are in impressive agreement in both cases. The clean surface reconstruction is determined with unprecedented accuracy. For the adsorbate, the analysis retrieves a simple Br-adlayer structure with the Br atoms residing in every second short bridge position on the close-packed Pt rows with the MR reconstruction lifted. The Br-Pt bond length $L=2.47\mathrm{}\hspace{0.5em}\mathrm{\AA }$ is almost equal to the sum of the atomic radii. The substrate below the adsorbate exhibits a contraction of the first layer spacing which amounts to half of that calculated for an unreconstructed clean surface.

• Received 14 September 2001

DOI:https://doi.org/10.1103/PhysRevB.65.165408