Calculations of helium diffraction intensities from clean and hydrogen-plated platinum

The scattering of helium atoms from both hydrogen-plated and clean platinum is studied theoretically by calculating the diffracted intensities. The hydrogen monolayer is modeled as either free hydrogen atoms or a layer of halves of hydrogen molecules. It is found that from the viewpoint of helium beam scattering there appears to be minimal charge transfer between the adsorbed hydrogen and the platinum substrate. It is also found that simple models of the clean platinum-helium interaction lead to poor agreement between theoretically calculated and experimental diffraction intensities.