Crystal structure of UO2SO4·2.5H2O: Full anisotropic refinement and vibration characteristics

UO2SO4·2.5H2O is monoclinic, space group P21/c (No. 14), unit-cell parameters of a = 6.7260(1)Å, b = 12.4210(2)Å, c = 16.8270(3)Å, β = 90.781(1)° with unit-cell volume V = 1405.66(4)Å3, Z = 8, Dcalc = 3.84 g/cm3. Two distinct uranium atoms, present as uranyl (UO2)2+, forming uranyl pentagonal bipyramids, two distinct sulfur atoms, forming sulfate tetrahedra and 17 oxygen atoms are present in the asymmetric part of its unit-cell. Two of oxygen atoms are water molecules bonded to the uranyl cation and one is water molecule bonded only by hydrogen-bonding. Crystal structure was refined fully anisotropically. Vibration modes of each molecular unit in Raman and infrared spectra were tentatively assigned and discussed, regarding refined structure. Inferred U-O lengths and hydrogen bond lengths are consistent with the crystal structure refinement.