Diffuse LEED and Surface Crystallography

Diffuse low-energy-electron diffraction measurements at 46 eV for a disordered O/W(100) surface at 120 K have been interpreted by theory to give the local geometry of the oxygen atoms. This first application of the technique shows that phonon scattering does not prevent interpretation of data, and demonstrates sensitivity to surface geometry comparable with that in conventional LEED experiments on ordered surfaces. $R$ factors for the optimum geometry are very low, indicating a highly reliable determination. The prospects for the use of this technique in a whole range of situations previously inaccessible to LEED are thereby opened.