Ho2Zr2O7 crystallizes in the orthorhombic Pmma space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form a mixture of distorted corner and edge-sharing HoO6 octahedra. The corner-sharing octahedral tilt angles are 68°. In the second Ho site, Ho(2) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms. In the second Zr site, Zr(2) is bonded in a body-centered cubic geometry to two equivalent O(3), two equivalent O(4), and four equivalent O(5) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ho(1) and two equivalent Zr(1) atoms to form OHo2Zr2 tetrahedra that share corners with two equivalent O(4)Zr4 tetrahedra, corners with four equivalent O(1)Ho2Zr2 tetrahedra, corners with four equivalent O(2)Ho3Zr tetrahedra, corners with four equivalent O(5)HoZr3 tetrahedra,  an edgeedge with one O(4)Zr4 tetrahedra, and edges with four equivalent O(2)Ho3Zr tetrahedra. In the second O site, O(2) is bonded to one Ho(2), two equivalent Ho(1), and one Zr(1) atom to form distorted OHo3Zr tetrahedra that share corners with two equivalent O(1)Ho2Zr2 tetrahedra, corners with two equivalent O(3)Ho2Zr2 tetrahedra, corners with two equivalent O(5)HoZr3 tetrahedra, corners with two equivalent O(4)Zr4 tetrahedra, corners with six equivalent O(2)Ho3Zr tetrahedra,  an edgeedge with one O(2)Ho3Zr tetrahedra,  an edgeedge with one O(5)HoZr3 tetrahedra, and edges with two equivalent O(1)Ho2Zr2 tetrahedra. In the third O site, O(3) is bonded to two equivalent Ho(2) and two equivalent Zr(2) atoms to form OHo2Zr2 tetrahedra that share corners with two equivalent O(4)Zr4 tetrahedra, corners with four equivalent O(3)Ho2Zr2 tetrahedra, corners with four equivalent O(2)Ho3Zr tetrahedra, corners with four equivalent O(5)HoZr3 tetrahedra,  an edgeedge with one O(4)Zr4 tetrahedra, and edges with four equivalent O(5)HoZr3 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Zr(1) and two equivalent Zr(2) atoms to form OZr4 tetrahedra that share corners with two equivalent O(1)Ho2Zr2 tetrahedra, corners with two equivalent O(3)Ho2Zr2 tetrahedra, corners with four equivalent O(2)Ho3Zr tetrahedra, corners with four equivalent O(5)HoZr3 tetrahedra, corners with four equivalent O(4)Zr4 tetrahedra,  an edgeedge with one O(1)Ho2Zr2 tetrahedra,  an edgeedge with one O(3)Ho2Zr2 tetrahedra, and edges with four equivalent O(5)HoZr3 tetrahedra. In the fifth O site, O(5) is bonded to one Ho(2), one Zr(1), and two equivalent Zr(2) atoms to form OHoZr3 tetrahedra that share corners with two equivalent O(1)Ho2Zr2 tetrahedra, corners with two equivalent O(3)Ho2Zr2 tetrahedra, corners with two equivalent O(2)Ho3Zr tetrahedra, corners with two equivalent O(4)Zr4 tetrahedra, corners with six equivalent O(5)HoZr3 tetrahedra,  an edgeedge with one O(2)Ho3Zr tetrahedra,  an edgeedge with one O(5)HoZr3 tetrahedra, edges with two equivalent O(3)Ho2Zr2 tetrahedra, and edges with two equivalent O(4)Zr4 tetrahedra.
Ho2Zr2O7 crystallizes in the orthorhombic Pmma space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form a mixture of distorted corner and edge-sharing HoO6 octahedra. The corner-sharing octahedral tilt angles are 68°. Both Ho(1)-O(1) bond lengths are 2.27 Å. All Ho(1)-O(2) bond lengths are 2.29 Å. In the second Ho site, Ho(2) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms. Both Ho(2)-O(2) bond lengths are 2.19 Å. Both Ho(2)-O(3) bond lengths are 2.17 Å. Both Ho(2)-O(5) bond lengths are 2.31 Å. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms. Both Zr(1)-O(1) bond lengths are 2.31 Å. Both Zr(1)-O(2) bond lengths are 2.58 Å. Both Zr(1)-O(4) bond lengths are 2.16 Å. Both Zr(1)-O(5) bond lengths are 2.19 Å. In the second Zr site, Zr(2) is bonded in a body-centered cubic geometry to two equivalent O(3), two equivalent O(4), and four equivalent O(5) atoms. Both Zr(2)-O(3) bond lengths are 2.22 Å. Both Zr(2)-O(4) bond lengths are 2.35 Å. All Zr(2)-O(5) bond lengths are 2.21 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ho(1) and two equivalent Zr(1) atoms to form OHo2Zr2 tetrahedra that share corners with two equivalent O(4)Zr4 tetrahedra, corners with four equivalent O(1)Ho2Zr2 tetrahedra, corners with four equivalent O(2)Ho3Zr tetrahedra, corners with four equivalent O(5)HoZr3 tetrahedra,  an edgeedge with one O(4)Zr4 tetrahedra, and edges with four equivalent O(2)Ho3Zr tetrahedra. In the second O site, O(2) is bonded to one Ho(2), two equivalent Ho(1), and one Zr(1) atom to form distorted OHo3Zr tetrahedra that share corners with two equivalent O(1)Ho2Zr2 tetrahedra, corners with two equivalent O(3)Ho2Zr2 tetrahedra, corners with two equivalent O(5)HoZr3 tetrahedra, corners with two equivalent O(4)Zr4 tetrahedra, corners with six equivalent O(2)Ho3Zr tetrahedra,  an edgeedge with one O(2)Ho3Zr tetrahedra,  an edgeedge with one O(5)HoZr3 tetrahedra, and edges with two equivalent O(1)Ho2Zr2 tetrahedra. In the third O site, O(3) is bonded to two equivalent Ho(2) and two equivalent Zr(2) atoms to form OHo2Zr2 tetrahedra that share corners with two equivalent O(4)Zr4 tetrahedra, corners with four equivalent O(3)Ho2Zr2 tetrahedra, corners with four equivalent O(2)Ho3Zr tetrahedra, corners with four equivalent O(5)HoZr3 tetrahedra,  an edgeedge with one O(4)Zr4 tetrahedra, and edges with four equivalent O(5)HoZr3 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Zr(1) and two equivalent Zr(2) atoms to form OZr4 tetrahedra that share corners with two equivalent O(1)Ho2Zr2 tetrahedra, corners with two equivalent O(3)Ho2Zr2 tetrahedra, corners with four equivalent O(2)Ho3Zr tetrahedra, corners with four equivalent O(5)HoZr3 tetrahedra, corners with four equivalent O(4)Zr4 tetrahedra,  an edgeedge with one O(1)Ho2Zr2 tetrahedra,  an edgeedge with one O(3)Ho2Zr2 tetrahedra, and edges with four equivalent O(5)HoZr3 tetrahedra. In the fifth O site, O(5) is bonded to one Ho(2), one Zr(1), and two equivalent Zr(2) atoms to form OHoZr3 tetrahedra that share corners with two equivalent O(1)Ho2Zr2 tetrahedra, corners with two equivalent O(3)Ho2Zr2 tetrahedra, corners with two equivalent O(2)Ho3Zr tetrahedra, corners with two equivalent O(4)Zr4 tetrahedra, corners with six equivalent O(5)HoZr3 tetrahedra,  an edgeedge with one O(2)Ho3Zr tetrahedra,  an edgeedge with one O(5)HoZr3 tetrahedra, edges with two equivalent O(3)Ho2Zr2 tetrahedra, and edges with two equivalent O(4)Zr4 tetrahedra.