UHfC2 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 Hf(1)C6 octahedra, edges with six equivalent U(1)C6 octahedra, and edges with six equivalent Hf(1)C6 octahedra. The corner-sharing octahedral tilt angles are 2°. Hf(1) is bonded to six equivalent C(1) atoms to form HfC6 octahedra that share corners with six equivalent U(1)C6 octahedra, edges with six equivalent U(1)C6 octahedra, and edges with six equivalent Hf(1)C6 octahedra. The corner-sharing octahedral tilt angles are 2°. C(1) is bonded to three equivalent U(1) and three equivalent Hf(1) atoms to form a mixture of edge and corner-sharing CHf3U3 octahedra. The corner-sharing octahedra are not tilted.
UHfC2 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 Hf(1)C6 octahedra, edges with six equivalent U(1)C6 octahedra, and edges with six equivalent Hf(1)C6 octahedra. The corner-sharing octahedral tilt angles are 2°. All U(1)-C(1) bond lengths are 2.43 Å. Hf(1) is bonded to six equivalent C(1) atoms to form HfC6 octahedra that share corners with six equivalent U(1)C6 octahedra, edges with six equivalent U(1)C6 octahedra, and edges with six equivalent Hf(1)C6 octahedra. The corner-sharing octahedral tilt angles are 2°. All Hf(1)-C(1) bond lengths are 2.36 Å. C(1) is bonded to three equivalent U(1) and three equivalent Hf(1) atoms to form a mixture of edge and corner-sharing CHf3U3 octahedra. The corner-sharing octahedra are not tilted.