On the fly first principles study of the classical scattering of an Ar atom from the LiF(100) surface

A density functional theory with dispersion corrections is used to study the scattering of an Ar atom on the LiF(100) surface. On the fly classical trajectories are propagated to study the in-plane angular and energy loss distributions of the scattered Ar atom. The computations are carried out for a frozen surface and a surface in which the crystal atoms are initially at T = 0 K. Two dimensional as well as three dimensional computations are presented. We find that the results agree qualitatively with measured experimental results. These computations show the impact of three dimensional effects on the scattering such as narrowing of the angular distance between rainbow peaks and inversion of asymmetry properties of the angular distribution. The computations also reaffirm the prediction that one should observe energy loss rainbows in the scattering of Ar from the LiF(100) surface.