High-energy-neutron vibrational spectroscopy onβ-V2H

By means of inelastic neutron scattering we investigated the localized H vibrations in β-${\mathrm{V}}_2$H (octahedral H sites). Using a unique single-domain single crystal, for the first time we determined the directions of the fundamental excitations of a hydrogen atom in a metal. Overtones of these vibrations were observed up to the fourteenth order. They establish a well-defined H potential up to more than 1 eV. The sequence of the excitations could be described in terms of an empirical potential.