Calculation of the atomic scattering factors of fast electrons at zero angle of incidence of an electron beam and mean inner crystal potentials

The atomic scattering factors of fast electrons at zero angle of incidence of an electron beam, f(el)(0), are calculated for neutral atoms with Z = 1-54, using the mean-square radii of electron-density distributions in atoms and ions, derived on the basis of the Hartree-Fock wave functions. The values of f(el)(0) have been calculated for the first time for some positive and negative ions. The obtained values of f(el)(0) were used to determine the mean inner potentials V-0 of metallic, covalent, and ionic crystals. The calculated values of V-0 are compared with the experimental data in the literature. The values of V-0 calculated for III-V and II-VI compounds are reported.