Na2UI6 is beta Vanadium nitride-derived structured and crystallizes in the trigonal R3 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to three equivalent I(1) and three equivalent I(2) atoms to form NaI6 octahedra that share corners with three equivalent Na(2)I6 octahedra, corners with six equivalent U(1)I6 octahedra, and  a faceface with one Na(2)I6 octahedra. The corner-sharing octahedral tilt angles range from 43-58°. In the second Na site, Na(2) is bonded to three equivalent I(1) and three equivalent I(2) atoms to form NaI6 octahedra that share corners with three equivalent Na(1)I6 octahedra, edges with three equivalent U(1)I6 octahedra, and  a faceface with one Na(1)I6 octahedra. The corner-sharing octahedral tilt angles are 58°. U(1) is bonded to three equivalent I(1) and three equivalent I(2) atoms to form UI6 octahedra that share corners with six equivalent Na(1)I6 octahedra and edges with three equivalent Na(2)I6 octahedra. The corner-sharing octahedral tilt angles are 43°. There are two inequivalent I sites. In the first I site, I(1) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one U(1) atom. In the second I site, I(2) is bonded in a distorted T-shaped geometry to one Na(1), one Na(2), and one U(1) atom.
Na2UI6 is beta Vanadium nitride-derived structured and crystallizes in the trigonal R3 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to three equivalent I(1) and three equivalent I(2) atoms to form NaI6 octahedra that share corners with three equivalent Na(2)I6 octahedra, corners with six equivalent U(1)I6 octahedra, and  a faceface with one Na(2)I6 octahedra. The corner-sharing octahedral tilt angles range from 43-58°. All Na(1)-I(1) bond lengths are 3.25 Å. All Na(1)-I(2) bond lengths are 3.28 Å. In the second Na site, Na(2) is bonded to three equivalent I(1) and three equivalent I(2) atoms to form NaI6 octahedra that share corners with three equivalent Na(1)I6 octahedra, edges with three equivalent U(1)I6 octahedra, and  a faceface with one Na(1)I6 octahedra. The corner-sharing octahedral tilt angles are 58°. All Na(2)-I(1) bond lengths are 3.18 Å. All Na(2)-I(2) bond lengths are 3.36 Å. U(1) is bonded to three equivalent I(1) and three equivalent I(2) atoms to form UI6 octahedra that share corners with six equivalent Na(1)I6 octahedra and edges with three equivalent Na(2)I6 octahedra. The corner-sharing octahedral tilt angles are 43°. All U(1)-I(1) bond lengths are 3.03 Å. All U(1)-I(2) bond lengths are 3.01 Å. There are two inequivalent I sites. In the first I site, I(1) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one U(1) atom. In the second I site, I(2) is bonded in a distorted T-shaped geometry to one Na(1), one Na(2), and one U(1) atom.