Ho8CoIn3 crystallizes in the hexagonal P6_3mc space group. There are four inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 3-coordinate geometry to one Co(1) and four equivalent In(1) atoms. In the second Ho site, Ho(2) is bonded in a 4-coordinate geometry to one Co(1) and four equivalent In(1) atoms. In the third Ho site, Ho(3) is bonded to one Co(1) and three equivalent In(1) atoms to form distorted corner-sharing HoIn3Co tetrahedra. The corner-sharing octahedral tilt angles range from 14-48°. In the fourth Ho site, Ho(4) is bonded to six equivalent In(1) atoms to form distorted HoIn6 octahedra that share corners with six equivalent Ho(3)In3Co tetrahedra and faces with two equivalent Ho(4)In6 octahedra. Co(1) is bonded in a 7-coordinate geometry to one Ho(3), three equivalent Ho(1), and three equivalent Ho(2) atoms. In(1) is bonded in a 11-coordinate geometry to one Ho(3), two equivalent Ho(4), four equivalent Ho(1), and four equivalent Ho(2) atoms.
Ho8CoIn3 crystallizes in the hexagonal P6_3mc space group. There are four inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 3-coordinate geometry to one Co(1) and four equivalent In(1) atoms. The Ho(1)-Co(1) bond length is 2.80 Å. There are two shorter (3.25 Å) and two longer (3.78 Å) Ho(1)-In(1) bond lengths. In the second Ho site, Ho(2) is bonded in a 4-coordinate geometry to one Co(1) and four equivalent In(1) atoms. The Ho(2)-Co(1) bond length is 2.80 Å. There are a spread of Ho(2)-In(1) bond distances ranging from 3.05-3.79 Å. In the third Ho site, Ho(3) is bonded to one Co(1) and three equivalent In(1) atoms to form distorted corner-sharing HoIn3Co tetrahedra. The corner-sharing octahedral tilt angles range from 14-48°. The Ho(3)-Co(1) bond length is 2.69 Å. All Ho(3)-In(1) bond lengths are 3.18 Å. In the fourth Ho site, Ho(4) is bonded to six equivalent In(1) atoms to form distorted HoIn6 octahedra that share corners with six equivalent Ho(3)In3Co tetrahedra and faces with two equivalent Ho(4)In6 octahedra. There are three shorter (3.35 Å) and three longer (3.42 Å) Ho(4)-In(1) bond lengths. Co(1) is bonded in a 7-coordinate geometry to one Ho(3), three equivalent Ho(1), and three equivalent Ho(2) atoms. In(1) is bonded in a 11-coordinate geometry to one Ho(3), two equivalent Ho(4), four equivalent Ho(1), and four equivalent Ho(2) atoms.