Azimuthal- and Polar-Angle-Dependent Surface Extended X-Ray—Absorption Fine-Structure Study: (2×1)O on Cu(110)

A low-symmetry twofold bridge site of (2×1) oxygen on Cu(110) allows the determination of the azimuthal dependence of the surface extended x-ray—absorption fine structure. For normal incidence and $\overrightarrow{\mathrm{E}}$ parallel to the [100] and [110] directions we determine the nearest- and second-nearest-neighbor distances to be 1.84(2) and 2.00(5) Å, respectively. We show that the atomic oxygen is occupying the low-symmetry twofold bridge site in the [100] direction 0.35 Å above the first Cu layer.