UNbC2 is Caswellsilverite structured and crystallizes in the trigonal R-3m space group. U(1) is bonded to six equivalent C(1) atoms to form UC6 octahedra that share corners with six equivalent Nb(1)C6 octahedra, edges with six equivalent U(1)C6 octahedra, and edges with six equivalent Nb(1)C6 octahedra. The corner-sharing octahedral tilt angles are 4°. Nb(1) is bonded to six equivalent C(1) atoms to form NbC6 octahedra that share corners with six equivalent U(1)C6 octahedra, edges with six equivalent U(1)C6 octahedra, and edges with six equivalent Nb(1)C6 octahedra. The corner-sharing octahedral tilt angles are 4°. C(1) is bonded to three equivalent U(1) and three equivalent Nb(1) atoms to form a mixture of corner and edge-sharing CU3Nb3 octahedra. The corner-sharing octahedra are not tilted.
UNbC2 is Caswellsilverite structured and crystallizes in the trigonal R-3m space group. U(1) is bonded to six equivalent C(1) atoms to form UC6 octahedra that share corners with six equivalent Nb(1)C6 octahedra, edges with six equivalent U(1)C6 octahedra, and edges with six equivalent Nb(1)C6 octahedra. The corner-sharing octahedral tilt angles are 4°. All U(1)-C(1) bond lengths are 2.41 Å. Nb(1) is bonded to six equivalent C(1) atoms to form NbC6 octahedra that share corners with six equivalent U(1)C6 octahedra, edges with six equivalent U(1)C6 octahedra, and edges with six equivalent Nb(1)C6 octahedra. The corner-sharing octahedral tilt angles are 4°. All Nb(1)-C(1) bond lengths are 2.29 Å. C(1) is bonded to three equivalent U(1) and three equivalent Nb(1) atoms to form a mixture of corner and edge-sharing CU3Nb3 octahedra. The corner-sharing octahedra are not tilted.