Crystal structure and profile fitting of Mg(OD)₂ by time-of-flight neutron diffraction

The crystal structure of Mg(OD)₂ has been refined from time-of-flight (TOF) neutron diffraction data. M_r = 60.304, trigonal, Pm1, a = 3.1455 (1), c = 4.7646 (3) Å, V = 40.831 (4) ų, Z = 4, D_x = 2.453 g cm⁻³, neutron time of flight, Rietveld refinement, R_wp = 3.84%, R_p = 2.83%, reduced χ² = 2.98 for 70 variables, data collected at 305 K. The O–D bond length is 0.937 (1) Å (0.956 Å corrected for `riding' motion). The use of a pseudo-Voigt profile function to allow for strain and particle-size broadening in TOF neutron diffraction of fine anisotropic powders is described.