
%0 Journal Article
%A Fender, BEF 
%A Figgis, BN 
%A Forsyth, JB 
%T Structure and Magnetization of (ND<sub>4</sub>)<sub>2</sub>Ni(SO<sub>4</sub>)<sub>2</sub>.6D<sub>2</sub>O And (NH<sub>4</sub>)<sub>2</sub>Ni(SO<sub>4</sub>)<sub>2</sub>.6H<sub>2</sub>O At 2-K by Neutron-Diffraction
%J Australian Journal of Chemistry
%D 1986/07/01
%V 39
%N 7
%P 1023-1028
%K 
%R https://doi.org/10.1071/CH9861023
%U https://www.publish.csiro.au/paper/CH9861023 
%X The structure of (ND4)2Ni(SO4)2.6D2O has been determined at 2 K by means of neutron diffraction using two crystals, one mounted about the b axis and one about the c axis, in normal-beam Weissenberg geometry. Totals of 642 and 689 averaged unique reflections were obtained and refined together, allowing differing scale and extinction parameters, to give R(F2) = 0.053. The weighted average cell dimensions and atomic positional parameters are reported. The crystals are monoclinic, P21/a; a 9.073, b 12.305, c 6.255 &#506;, &#946; 106.9&#176;. The structure is compared to that obtained by X-ray diffraction at c. 295 K. The similarity of the structure, including the hydrogen bonding, to that of the manganese compound, is very great, apart from the metal-oxygen bond lengths. The structure of (NH4)2Ni(SO4)2.6D2O was obtained by the study of one crystal mounted down the c axis, collecting only the hk0 and hk1 layers, also at 2 K. A total of 441 averaged unique reflections were obtained, and the structure refined to Rw(F2) = 0.043. Given the poor resolution in the c direction, the resultant structure is almost indistinguishable from that of the deuterated compound, except that the NiO6 octahedron seems more regular. The magnetization at 2.00 K and 4.60 T is shown to be in reasonable agreement with the value expected from the 90 K E.S.R . z.f.s . parameters, and the experimentally observed 8% difference between the deuterated and hydrogenous salts could well arise from a difference in z.f.s .parameters consequent upon the structural alterations. 
