Gd2Hf2O7 crystallizes in the cubic Fd-3m space group. Gd(1) is bonded in a body-centered cubic geometry to two equivalent O(2) and six equivalent O(1) atoms. Hf(1) is bonded to six equivalent O(1) atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Gd(1) and two equivalent Hf(1) atoms to form distorted OGd2Hf2 tetrahedra that share corners with two equivalent O(2)Gd4 tetrahedra, corners with twelve equivalent O(1)Gd2Hf2 tetrahedra,  an edgeedge with one O(2)Gd4 tetrahedra, and edges with four equivalent O(1)Gd2Hf2 tetrahedra. In the second O site, O(2) is bonded to four equivalent Gd(1) atoms to form OGd4 tetrahedra that share corners with four equivalent O(2)Gd4 tetrahedra, corners with twelve equivalent O(1)Gd2Hf2 tetrahedra, and edges with six equivalent O(1)Gd2Hf2 tetrahedra.
Gd2Hf2O7 crystallizes in the cubic Fd-3m space group. Gd(1) is bonded in a body-centered cubic geometry to two equivalent O(2) and six equivalent O(1) atoms. Both Gd(1)-O(2) bond lengths are 2.28 Å. All Gd(1)-O(1) bond lengths are 2.54 Å. Hf(1) is bonded to six equivalent O(1) atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles are 52°. All Hf(1)-O(1) bond lengths are 2.06 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Gd(1) and two equivalent Hf(1) atoms to form distorted OGd2Hf2 tetrahedra that share corners with two equivalent O(2)Gd4 tetrahedra, corners with twelve equivalent O(1)Gd2Hf2 tetrahedra,  an edgeedge with one O(2)Gd4 tetrahedra, and edges with four equivalent O(1)Gd2Hf2 tetrahedra. In the second O site, O(2) is bonded to four equivalent Gd(1) atoms to form OGd4 tetrahedra that share corners with four equivalent O(2)Gd4 tetrahedra, corners with twelve equivalent O(1)Gd2Hf2 tetrahedra, and edges with six equivalent O(1)Gd2Hf2 tetrahedra.