Dynamical Calculations of Low-Energy Electron Diffraction for Incommensurate Lattice Structures—Xe on Ag(111)

Dynamical calculations of low-energy-electron-diffraction intensity-voltage curves are carried out for the first time for the case of an incommensurate overlayer-substrate system, Xe-Ag(111). A new scheme was developed to take into account that the substrate (or overlayer) has incident upon it electron beams at angles unrelated to those angles into which the substrate (overlayer) itself diffracts beams. Comparing the calculated curves with experiment, a Xe-Ag(111) spacing of 3.55 ±{} 0.1 {} is determined.