Crystal structure ofYD1.96andYH1.98by neutron diffraction

The crystal structure of ${\mathrm{YD}}_{1.96}$ and ${\mathrm{YH}}_{1.98}$ has been examined at room temperature and 11 K by neutron-diffraction techniques. Refinement of the data reveals the occupation of both tetrahedral and octahedral interstices of the fcc metal lattice. These results help to explain some features observed in the optical properties of ${\mathrm{YH}}_x$.