Vibrational spectrum of magnesium hydride

The vibrational spectrum of hydrogen atoms in magnesium hydride has been st udied by means of inelastic-neutron and Raman-scattering experiments betwee n 12 and 295 K. After careful evaluation of multiple scattering and multiph onon contributions, we provide a vibrational frequency spectrum up to 180 m eV and the mean-square displacement of hydrogen atoms. The inelastic light scattering spectra of MgH2 powders show three Raman allowed modes (A(1g), B -1g, and E-g) and some smaller features that can be related with second-ord er and disorder-induced processes.