Role of the potential in LEED; application to the Na(110) surface

A study of the exchange and correlation component of the one-electron LEED potential was carried out. An analysis of low-energy electron diffraction data from the Na(110) face at T=173K and normal incidence was made to test the different model potentials. A good fit to experimental spectra was obtained with a model based upon Hartree-Fock (core) and Hedin and Lundqvist results for the exchange and correlation potential of a uniform electron gas. The inner potential and absorption are those of a uniform electron gas with the same density as Na (r s =4). The surface layer is determined to be neither contracted nor dilated with respect to the bulk (110) planes.