Layer stacking implementation of tensor low energy electron diffraction

The introduction of the tensor low energy electronic diffraction (TLEED) approximation greatly enhances the computational efficiency of the scattering calculations required to determine surface structure from electron diffraction data. This increase in efficiency has resulted in complex surface structures being routinely solved. The formalism originally applied to the TLEED methodology requires an initial multiple scattering calculation on a reference structure using the renormalized forward scattering approximation (RFS) to model the multiple scattering in the near surface region of a crystal. However, RFS diverges when the spacing between the atomic planes normal to the surface becomes less than approximately an angstrom. This article describes a TLEED implementation that is based on the Barbieri/Van Hove symmetrized automated LEED package and that incorporates the self-consistent layer stacking approximation for the reference structure. This method does not break down as rapidly as RFS and permits the TLEED approximation to be extended to materials with smaller interlayer distances.