The crystal structure of Zr2NiD4

The crystal structure of Zr2NiD4 at room temperature has been investigated by high resolution neutron powder diffraction. The diffraction pattern has been successfully fitted on the basis of a monoclinic structure in space group I2/c with cell parameters a = 0.6789 nm, b = 0.6758 nm, c = 0.5675 nm, beta = 91.04 degrees relative to the neutron wavelength of 0.1893(1) nm. The site occupancies of the deuterium atoms are compared with model calculations and results from previous X-ray and neutron data from Zr2Ni hydrides and deuterides of similar compositions based on the similar tetragonal CuAl2-type structure of Zr2Ni.