  Pairwise additive potentials for multielectronic atoms interacting with a
LiF(001) surface are revisited by including an improved description of the
electron density associated with the different lattice sites, as well as
non-local electron density contributions. Within this model, the electron
distribution around each ionic site of the crystal is described by means of an
onion approach that accounts for the influence of the Madelung potential. From
such densities, binary interatomic potentials are then derived by using
well-known non-local functionals for the kinetic, exchange and correlation
terms. Rumpling and long-range contributions due to projectile polarization and
van der Waals forces are also included in an analogous fashion. We apply this
pairwise additive approximation to evaluate the interaction potential between
closed-shell - He, Ne, Ar, Kr, and Xe - and open-shell - N, S, and Cl - atoms
and the LiF surface, analyzing the relative importance of the different
contributions. The performance of the proposed potentials is assessed by
contrasting angular positions of rainbow and supernumerary rainbow maxima
produced by fast grazing incidence with available experimental data. The good
agreement found for normal energies in the eV- range represents a meaningful
evidence of the quality of the present description.
