Dynamical low energy electron diffraction methods

The authors present and discuss theoretical techniques that considerably increase the power of dynamical leed calculations, particularly in the layer treatment of surfaces. Their wide applicability makes them especially suitable for surface structural determination. The layer doubling method is an efficient and accurate way of calculating reflectivities off a stack of identical atomic layers requiring only finite absorption for convergence. Layer summation over surface-induced sublattices avoids the repetition of lengthy summations when the surface has a different two-dimensional unit cell from the substrate. The exploitation of symmetry finally can give spectacular reductions in computing time.