Dynamical effects as a window into van der Waals interactions in grazing-incidence fast He-atom diffraction from KCl(001)

In this paper we address, both experimentally and theoretically, the very grazing scattering of He atoms off KCl(001) with incidence along $\ensuremath{\langle}100\ensuremath{\rangle}$ channel. Our theoretical model combines a semiquantum description dynamics high-precision interaction potential. By means thorough analysis quantum phase for in-plane rainbow trajectories, are able to connect presence physisorption well significant enhancements corrugation angle, relative hard corrugated wall predictions. We trace connection dynamical effects on incident scattered beams due their traversing well. Finally, show that inclusion van der Waals interactions in potential improves accord experiments angle.