Cs-Induced Relaxation of the Cu(110) Surface

The relaxations of a series of ( $1\times n$) structures of the Cu(110) surface with $n=1\mathrm{}$, 3, 2, and 3, induced by Cs adsorption, are studied with x-ray diffraction. The distances of the topmost Cu atoms towards their underlying nearest neighbors decrease significantly with more extensive reconstruction, despite the fact that the first shell coordination of these top-layer Cu atoms does not change. Simple coordination arguments do not account for the observed trend, whereas the polarization in the surface, which is expected to increase with more extensive reconstruction, could provide an explanation.