U2N3 crystallizes in the trigonal P-3m1 space group. U(1) is bonded in a 7-coordinate geometry to three equivalent N(1) and four equivalent N(2) atoms. There are two inequivalent N sites. In the first N site, N(1) is bonded to six equivalent U(1) atoms to form NU6 octahedra that share corners with twelve equivalent N(2)U4 tetrahedra, edges with six equivalent N(1)U6 octahedra, and edges with six equivalent N(2)U4 tetrahedra. In the second N site, N(2) is bonded to four equivalent U(1) atoms to form NU4 tetrahedra that share corners with six equivalent N(1)U6 octahedra, corners with six equivalent N(2)U4 tetrahedra, edges with three equivalent N(1)U6 octahedra, and edges with three equivalent N(2)U4 tetrahedra. The corner-sharing octahedral tilt angles range from 16-57°.
U2N3 crystallizes in the trigonal P-3m1 space group. U(1) is bonded in a 7-coordinate geometry to three equivalent N(1) and four equivalent N(2) atoms. All U(1)-N(1) bond lengths are 2.55 Å. There are three shorter (2.23 Å) and one longer (2.33 Å) U(1)-N(2) bond length. There are two inequivalent N sites. In the first N site, N(1) is bonded to six equivalent U(1) atoms to form NU6 octahedra that share corners with twelve equivalent N(2)U4 tetrahedra, edges with six equivalent N(1)U6 octahedra, and edges with six equivalent N(2)U4 tetrahedra. In the second N site, N(2) is bonded to four equivalent U(1) atoms to form NU4 tetrahedra that share corners with six equivalent N(1)U6 octahedra, corners with six equivalent N(2)U4 tetrahedra, edges with three equivalent N(1)U6 octahedra, and edges with three equivalent N(2)U4 tetrahedra. The corner-sharing octahedral tilt angles range from 16-57°.