The angular dependence of low-energy-electron-diffraction spectra from AG{001} is reexamined. The energy dependence of the imaginary part of the scattering potential is determined by comparing the measured total elastic current reflected by the surface with that calculated for a rigid lattice, thereby substantially removing the dependence on lattice motion and surface roughness. This energy-dependent complex potential is then used to calculate several specular and nonspecular spectra for incident angles up to 50°. Except for the spectra at 50° incidence, all calculated spectra are in very good agreement with the observed spectra as far as peak positions and shapes are concerned. As expected, the observed intensities are always somewhat less than calculated intensities because of the imperfections of the surface used in the experiment.

• Received 30 April 1973

DOI:https://doi.org/10.1103/PhysRevB.8.5523