Fast perturbation schemes for low energy electron diffraction spectra

A careful analysis is made of the convergence of several perturbative techniques for calculating LEED intensities with the hope of finding a scheme that is both fast and accurate. Carefully calculated scattering factors are used in this analysis. Unfortunately divergence, or poor convergence of the relevant series holds for most theories. However a renormalization for the forward scattering (RFS) results in a highly convergent series (RFS perturbation theory) that is amenable to rapid calculations.