The crystal structure of lithium uranate

Abstract Lithium uranate, Li 2 UO 4 , crystallizes in an orthorhombic unit cell, space group, Pnma (D 2h 16 , No. 62) with a =10.547(3), b = 6.065(1), c = 5.134(1) A and Z = 4. Single crystal X-ray diffraction data complete to 2θ = 50° were collected on a Syntex P2 1 , automated diffractometer. The structure was solved by a combination of Patterson, Fourier, and least-squares refinement techniques to an R F = 0.061 for 321 independent reflections. The structure consists of octahedrally coordinated U(VI) ions bonded to two crystallographically different primary oxygens at distances of 1.97(2) and 1.92(2) A and to four equivalent secondary oxygens at 2.19(1) A. Octahedrally coordinated Li(1) and tetrahedrally coordinated Li(2) form LiO bonds of lengths varying from 1.91(5) to 2.29(2) A.