Ho3Co11B4 crystallizes in the hexagonal P6/mmm space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 6-coordinate geometry to six equivalent Co(1) atoms. In the second Ho site, Ho(2) is bonded in a 18-coordinate geometry to six equivalent Co(2), six equivalent Co(3), and six equivalent B(1) atoms. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to three equivalent Ho(1) and six equivalent Co(3) atoms. In the second Co site, Co(2) is bonded in a distorted square co-planar geometry to four equivalent Ho(2) and four equivalent B(1) atoms. In the third Co site, Co(3) is bonded in a distorted L-shaped geometry to two equivalent Ho(2), two equivalent Co(1), and two equivalent B(1) atoms. B(1) is bonded in a 6-coordinate geometry to three equivalent Ho(2), three equivalent Co(2), and three equivalent Co(3) atoms.
Ho3Co11B4 crystallizes in the hexagonal P6/mmm space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 6-coordinate geometry to six equivalent Co(1) atoms. All Ho(1)-Co(1) bond lengths are 2.91 Å. In the second Ho site, Ho(2) is bonded in a 18-coordinate geometry to six equivalent Co(2), six equivalent Co(3), and six equivalent B(1) atoms. All Ho(2)-Co(2) bond lengths are 2.96 Å. All Ho(2)-Co(3) bond lengths are 2.86 Å. All Ho(2)-B(1) bond lengths are 2.91 Å. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to three equivalent Ho(1) and six equivalent Co(3) atoms. All Co(1)-Co(3) bond lengths are 2.46 Å. In the second Co site, Co(2) is bonded in a distorted square co-planar geometry to four equivalent Ho(2) and four equivalent B(1) atoms. All Co(2)-B(1) bond lengths are 2.07 Å. In the third Co site, Co(3) is bonded in a distorted L-shaped geometry to two equivalent Ho(2), two equivalent Co(1), and two equivalent B(1) atoms. Both Co(3)-B(1) bond lengths are 2.05 Å. B(1) is bonded in a 6-coordinate geometry to three equivalent Ho(2), three equivalent Co(2), and three equivalent Co(3) atoms.