Ho3MoB7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 10-coordinate geometry to one B(4), four equivalent B(3), and six equivalent B(2) atoms. In the second Ho site, Ho(2) is bonded in a 11-coordinate geometry to two equivalent B(3), two equivalent B(4), three equivalent B(2), and four equivalent B(1) atoms. Mo(1) is bonded in a 10-coordinate geometry to two equivalent B(4), four equivalent B(1), and four equivalent B(3) atoms. There are four inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to four equivalent Ho(2), two equivalent Mo(1), one B(1), one B(3), and one B(4) atom. In the second B site, B(2) is bonded in a 9-coordinate geometry to three equivalent Ho(1), three equivalent Ho(2), one B(3), and two equivalent B(2) atoms. In the third B site, B(3) is bonded in a 9-coordinate geometry to two equivalent Ho(1), two equivalent Ho(2), two equivalent Mo(1), one B(1), one B(2), and one B(3) atom. In the fourth B site, B(4) is bonded in a 9-coordinate geometry to one Ho(1), four equivalent Ho(2), two equivalent Mo(1), and two equivalent B(1) atoms.
Ho3MoB7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 10-coordinate geometry to one B(4), four equivalent B(3), and six equivalent B(2) atoms. The Ho(1)-B(4) bond length is 3.38 Å. All Ho(1)-B(3) bond lengths are 2.63 Å. There are four shorter (2.69 Å) and two longer (2.72 Å) Ho(1)-B(2) bond lengths. In the second Ho site, Ho(2) is bonded in a 11-coordinate geometry to two equivalent B(3), two equivalent B(4), three equivalent B(2), and four equivalent B(1) atoms. Both Ho(2)-B(3) bond lengths are 2.65 Å. Both Ho(2)-B(4) bond lengths are 2.68 Å. There is one shorter (2.65 Å) and two longer (2.74 Å) Ho(2)-B(2) bond lengths. There are two shorter (2.64 Å) and two longer (2.67 Å) Ho(2)-B(1) bond lengths. Mo(1) is bonded in a 10-coordinate geometry to two equivalent B(4), four equivalent B(1), and four equivalent B(3) atoms. Both Mo(1)-B(4) bond lengths are 2.33 Å. All Mo(1)-B(1) bond lengths are 2.35 Å. All Mo(1)-B(3) bond lengths are 2.37 Å. There are four inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to four equivalent Ho(2), two equivalent Mo(1), one B(1), one B(3), and one B(4) atom. The B(1)-B(1) bond length is 1.84 Å. The B(1)-B(3) bond length is 1.91 Å. The B(1)-B(4) bond length is 1.81 Å. In the second B site, B(2) is bonded in a 9-coordinate geometry to three equivalent Ho(1), three equivalent Ho(2), one B(3), and two equivalent B(2) atoms. The B(2)-B(3) bond length is 1.83 Å. Both B(2)-B(2) bond lengths are 1.97 Å. In the third B site, B(3) is bonded in a 9-coordinate geometry to two equivalent Ho(1), two equivalent Ho(2), two equivalent Mo(1), one B(1), one B(2), and one B(3) atom. The B(3)-B(3) bond length is 1.95 Å. In the fourth B site, B(4) is bonded in a 9-coordinate geometry to one Ho(1), four equivalent Ho(2), two equivalent Mo(1), and two equivalent B(1) atoms.