HoDyO3 crystallizes in the hexagonal P6_3cm space group. Ho(1) is bonded to one O(1), one O(2), one O(4), and two equivalent O(3) atoms to form corner-sharing HoO5 trigonal bipyramids. There are two inequivalent Dy sites. In the first Dy site, Dy(1) is bonded in a 7-coordinate geometry to one O(3), three equivalent O(1), and three equivalent O(2) atoms. In the second Dy site, Dy(2) is bonded in a 7-coordinate geometry to one O(4), three equivalent O(1), and three equivalent O(2) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Ho(1), one Dy(2), and two equivalent Dy(1) atoms to form ODy3Ho tetrahedra that share corners with two equivalent O(4)DyHo3 tetrahedra, corners with four equivalent O(2)Dy3Ho tetrahedra, corners with six equivalent O(1)Dy3Ho tetrahedra, edges with three equivalent O(2)Dy3Ho tetrahedra, and edges with two equivalent O(3)DyHo3 trigonal pyramids. In the second O site, O(2) is bonded to one Ho(1), one Dy(2), and two equivalent Dy(1) atoms to form ODy3Ho tetrahedra that share corners with four equivalent O(1)Dy3Ho tetrahedra, corners with six equivalent O(2)Dy3Ho tetrahedra, corners with four equivalent O(3)DyHo3 trigonal pyramids,  an edgeedge with one O(4)DyHo3 tetrahedra, and edges with three equivalent O(1)Dy3Ho tetrahedra. In the third O site, O(3) is bonded to three equivalent Ho(1) and one Dy(1) atom to form distorted ODyHo3 trigonal pyramids that share corners with three equivalent O(4)DyHo3 tetrahedra, corners with six equivalent O(2)Dy3Ho tetrahedra, corners with three equivalent O(3)DyHo3 trigonal pyramids, and edges with three equivalent O(1)Dy3Ho tetrahedra. In the fourth O site, O(4) is bonded to three equivalent Ho(1) and one Dy(2) atom to form ODyHo3 tetrahedra that share corners with six equivalent O(1)Dy3Ho tetrahedra, corners with six equivalent O(3)DyHo3 trigonal pyramids, and edges with three equivalent O(2)Dy3Ho tetrahedra.
HoDyO3 crystallizes in the hexagonal P6_3cm space group. Ho(1) is bonded to one O(1), one O(2), one O(4), and two equivalent O(3) atoms to form corner-sharing HoO5 trigonal bipyramids. The Ho(1)-O(1) bond length is 2.22 Å. The Ho(1)-O(2) bond length is 2.20 Å. The Ho(1)-O(4) bond length is 2.19 Å. Both Ho(1)-O(3) bond lengths are 2.17 Å. There are two inequivalent Dy sites. In the first Dy site, Dy(1) is bonded in a 7-coordinate geometry to one O(3), three equivalent O(1), and three equivalent O(2) atoms. The Dy(1)-O(3) bond length is 2.69 Å. All Dy(1)-O(1) bond lengths are 2.38 Å. All Dy(1)-O(2) bond lengths are 2.35 Å. In the second Dy site, Dy(2) is bonded in a 7-coordinate geometry to one O(4), three equivalent O(1), and three equivalent O(2) atoms. The Dy(2)-O(4) bond length is 2.50 Å. All Dy(2)-O(1) bond lengths are 2.30 Å. All Dy(2)-O(2) bond lengths are 2.46 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Ho(1), one Dy(2), and two equivalent Dy(1) atoms to form ODy3Ho tetrahedra that share corners with two equivalent O(4)DyHo3 tetrahedra, corners with four equivalent O(2)Dy3Ho tetrahedra, corners with six equivalent O(1)Dy3Ho tetrahedra, edges with three equivalent O(2)Dy3Ho tetrahedra, and edges with two equivalent O(3)DyHo3 trigonal pyramids. In the second O site, O(2) is bonded to one Ho(1), one Dy(2), and two equivalent Dy(1) atoms to form ODy3Ho tetrahedra that share corners with four equivalent O(1)Dy3Ho tetrahedra, corners with six equivalent O(2)Dy3Ho tetrahedra, corners with four equivalent O(3)DyHo3 trigonal pyramids,  an edgeedge with one O(4)DyHo3 tetrahedra, and edges with three equivalent O(1)Dy3Ho tetrahedra. In the third O site, O(3) is bonded to three equivalent Ho(1) and one Dy(1) atom to form distorted ODyHo3 trigonal pyramids that share corners with three equivalent O(4)DyHo3 tetrahedra, corners with six equivalent O(2)Dy3Ho tetrahedra, corners with three equivalent O(3)DyHo3 trigonal pyramids, and edges with three equivalent O(1)Dy3Ho tetrahedra. In the fourth O site, O(4) is bonded to three equivalent Ho(1) and one Dy(2) atom to form ODyHo3 tetrahedra that share corners with six equivalent O(1)Dy3Ho tetrahedra, corners with six equivalent O(3)DyHo3 trigonal pyramids, and edges with three equivalent O(2)Dy3Ho tetrahedra.