Determination of the Cu(110)-c(6×2)-O structure by x-ray diffraction

We have performed a structural determination of the Cu(110)-c(6×2)-O surface by x-ray diffraction. A model including only copper atoms is found on the basis of the Patterson function; the positions of the oxygen atoms are revealed in an electron-density-difference map. The final structure has a reduced mean-square residual of ${\mathrm{\chi }}^2$=1.9, and includes most of the features known from the literature, with 5/6 of a monolayer of Cu atoms considerably displaced away from ideal lattice sites, two different oxygen sites, and an oxygen coverage of 2/3 of a monolayer. The structure contains Cu-O chains as found on the Cu(110)-(2×1)-O and Cu(100)-(√2 ×2 √2 )R45°-O surfaces, but they are more densely packed than in the 2×1 structure.