The crystal structure of thorium and zirconium dihydrides by X-ray and neutron diffraction

Abstract

Thorium forms a tetragonal lower hydride of composition ThtI~. The hydrides ThH2, ThI)2 and ZrD9 have been studied by neutron diffraction in order that hydrogen positions could be determined. The hydrides are isomorphons, and have a deformed fluorite structure. Metal-hydrogen distances in thorium hydride are unusually large, as in UHs. Thorium and zirconium scattering amplitudes and a revised scattering amplitude for deuterium are reported.