HoCuSe2 crystallizes in the trigonal P-3m1 space group. Ho(1) is bonded to six equivalent Se(1) atoms to form distorted HoSe6 octahedra that share corners with twelve equivalent Cu(1)Se6 octahedra, edges with six equivalent Ho(1)Se6 octahedra, and faces with two equivalent Cu(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 49°. Cu(1) is bonded to six equivalent Se(1) atoms to form distorted CuSe6 octahedra that share corners with twelve equivalent Ho(1)Se6 octahedra, edges with six equivalent Cu(1)Se6 octahedra, and faces with two equivalent Ho(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 49°. Se(1) is bonded in a 6-coordinate geometry to three equivalent Ho(1) and three equivalent Cu(1) atoms.
HoCuSe2 crystallizes in the trigonal P-3m1 space group. Ho(1) is bonded to six equivalent Se(1) atoms to form distorted HoSe6 octahedra that share corners with twelve equivalent Cu(1)Se6 octahedra, edges with six equivalent Ho(1)Se6 octahedra, and faces with two equivalent Cu(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 49°. All Ho(1)-Se(1) bond lengths are 2.86 Å. Cu(1) is bonded to six equivalent Se(1) atoms to form distorted CuSe6 octahedra that share corners with twelve equivalent Ho(1)Se6 octahedra, edges with six equivalent Cu(1)Se6 octahedra, and faces with two equivalent Ho(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 49°. All Cu(1)-Se(1) bond lengths are 2.72 Å. Se(1) is bonded in a 6-coordinate geometry to three equivalent Ho(1) and three equivalent Cu(1) atoms.