The interaction of atoms with LiF(001) revisited

TL;DR

This paper develops improved pairwise additive potentials for atom-LiF(001) interactions, incorporating detailed electron density models and non-local effects, and validates them against experimental scattering data.

Contribution

It introduces a refined electron density-based model for atom-surface interactions, including non-local effects and polarization, enhancing accuracy over previous approaches.

Findings

Accurately predicts angular positions of rainbow maxima in atom-surface scattering.

Demonstrates good agreement with experimental data for normal energies in the eV range.

Highlights the importance of non-local and polarization effects in modeling atom-surface interactions.

Abstract

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.