Structure of URuAl by single-crystal neutron diffraction at 120 K

URuAl, Mr = 366.1, hexagonal, P[unk]2m (I.T., nb. 189), a = 6.866(5) Å, c = 4.026(3) Å, V = 164.4(2) Å3, Z = 3, Dx = 11.1 g cm−3, neutron diffraction, λ = 0.8308(2) Å,μ = 0.0188 mm−1,|F(000)| = 5.630×10−14 m, T = 120(2) K, R(F 2) = 0.0196, w R(F 2) = 0.0291, S = 1.077 for 429 reflections with I > 3σ(I) out of 442 measured reflections. HoNiAl type of structure, U-Ru layers alternating with Ru-Al layers. Two distinct atomic sites are occupied by the transition metal atom. A refinement of the neutron coherent scattering length for the ruthenium element (b Ru = 6.94(3) fm) is reported.