New Perturbation Theory for Low-Energy Electron-Diffraction Intensities

Standard perturbation theory applied to the low-energy electron-diffraction problem does not appear to give accurate results even when carried to second order. A new scheme, renormalized forward-scattering perturbation theory, retains the advantage of being fast to execute, but at the same time is very accurate. The new theory is subjected to the stringent test of comparison with exact results for a realistic model of the copper (100) surface.