Ho4(B2O5)3 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(6), one O(7), and two equivalent O(2) atoms. In the second Ho site, Ho(2) is bonded in a 8-coordinate geometry to one O(5), one O(8), two equivalent O(1), two equivalent O(4), and two equivalent O(7) atoms. There are three inequivalent B sites. In the first B site, B(1) is bonded to one O(5), one O(6), and two equivalent O(2) atoms to form a mixture of corner and edge-sharing BO4 tetrahedra. In the second B site, B(2) is bonded to one O(3), one O(4), one O(7), and one O(8) atom to form corner-sharing BO4 tetrahedra. In the third B site, B(3) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form corner-sharing BO4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(8) is bonded in a 4-coordinate geometry to two equivalent Ho(2) and two equivalent B(2) atoms. In the second O site, O(1) is bonded in a 4-coordinate geometry to one Ho(1), two equivalent Ho(2), and one B(3) atom. In the third O site, O(2) is bonded in a distorted L-shaped geometry to two equivalent Ho(1) and two equivalent B(1) atoms. In the fourth O site, O(3) is bonded in a 3-coordinate geometry to one Ho(1), one B(2), and one B(3) atom. In the fifth O site, O(4) is bonded in a 4-coordinate geometry to one Ho(1), two equivalent Ho(2), and one B(2) atom. In the sixth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ho(1), one Ho(2), one B(1), and one B(3) atom. In the seventh O site, O(6) is bonded in a 3-coordinate geometry to one Ho(1), one B(1), and one B(3) atom. In the eighth O site, O(7) is bonded in a 4-coordinate geometry to one Ho(1), two equivalent Ho(2), and one B(2) atom.
Ho4(B2O5)3 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(6), one O(7), and two equivalent O(2) atoms. The Ho(1)-O(1) bond length is 2.22 Å. The Ho(1)-O(3) bond length is 2.23 Å. The Ho(1)-O(4) bond length is 2.27 Å. The Ho(1)-O(5) bond length is 2.68 Å. The Ho(1)-O(6) bond length is 2.29 Å. The Ho(1)-O(7) bond length is 2.47 Å. There is one shorter (2.57 Å) and one longer (2.60 Å) Ho(1)-O(2) bond length. In the second Ho site, Ho(2) is bonded in a 8-coordinate geometry to one O(5), one O(8), two equivalent O(1), two equivalent O(4), and two equivalent O(7) atoms. The Ho(2)-O(5) bond length is 2.63 Å. The Ho(2)-O(8) bond length is 2.35 Å. There is one shorter (2.36 Å) and one longer (2.61 Å) Ho(2)-O(1) bond length. There is one shorter (2.25 Å) and one longer (2.52 Å) Ho(2)-O(4) bond length. There is one shorter (2.25 Å) and one longer (2.51 Å) Ho(2)-O(7) bond length. There are three inequivalent B sites. In the first B site, B(1) is bonded to one O(5), one O(6), and two equivalent O(2) atoms to form a mixture of corner and edge-sharing BO4 tetrahedra. The B(1)-O(5) bond length is 1.46 Å. The B(1)-O(6) bond length is 1.46 Å. There is one shorter (1.51 Å) and one longer (1.55 Å) B(1)-O(2) bond length. In the second B site, B(2) is bonded to one O(3), one O(4), one O(7), and one O(8) atom to form corner-sharing BO4 tetrahedra. The B(2)-O(3) bond length is 1.51 Å. The B(2)-O(4) bond length is 1.44 Å. The B(2)-O(7) bond length is 1.46 Å. The B(2)-O(8) bond length is 1.52 Å. In the third B site, B(3) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form corner-sharing BO4 tetrahedra. The B(3)-O(1) bond length is 1.46 Å. The B(3)-O(3) bond length is 1.48 Å. The B(3)-O(5) bond length is 1.51 Å. The B(3)-O(6) bond length is 1.48 Å. There are eight inequivalent O sites. In the first O site, O(8) is bonded in a 4-coordinate geometry to two equivalent Ho(2) and two equivalent B(2) atoms. In the second O site, O(1) is bonded in a 4-coordinate geometry to one Ho(1), two equivalent Ho(2), and one B(3) atom. In the third O site, O(2) is bonded in a distorted L-shaped geometry to two equivalent Ho(1) and two equivalent B(1) atoms. In the fourth O site, O(3) is bonded in a 3-coordinate geometry to one Ho(1), one B(2), and one B(3) atom. In the fifth O site, O(4) is bonded in a 4-coordinate geometry to one Ho(1), two equivalent Ho(2), and one B(2) atom. In the sixth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ho(1), one Ho(2), one B(1), and one B(3) atom. In the seventh O site, O(6) is bonded in a 3-coordinate geometry to one Ho(1), one B(1), and one B(3) atom. In the eighth O site, O(7) is bonded in a 4-coordinate geometry to one Ho(1), two equivalent Ho(2), and one B(2) atom.