We introduce a universal and fully ab initio theory for inelastic scattering
of any atom from any surface, and apply the theory to helium scattering from
Nb(100). The key aspect making our approach universal is a direct
first-principles evaluation of the scattering atom-electron vertex. By
correcting misleading results from current state-of-the-art theories, this
fully ab initio approach will be critical in guiding and interpreting
experiments that adopt next-generation, non-destructive atomic beam scattering.Comment: 6 pages, 5 figure