Gd3ReO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. In the second Gd site, Gd(2) is bonded to one O(3), two equivalent O(1), and four equivalent O(2) atoms to form distorted GdO7 pentagonal bipyramids that share corners with two equivalent Re(1)O6 octahedra, corners with three equivalent Gd(2)O7 pentagonal bipyramids, edges with two equivalent Re(1)O6 octahedra, and edges with two equivalent Gd(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 43°. Re(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form ReO6 octahedra that share corners with two equivalent Re(1)O6 octahedra, corners with four equivalent Gd(2)O7 pentagonal bipyramids, and edges with four equivalent Gd(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 22°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Gd(1) and two equivalent Gd(2) atoms to form OGd4 tetrahedra that share corners with six equivalent O(1)Gd4 tetrahedra, corners with eight equivalent O(2)Gd3Re tetrahedra,  an edgeedge with one O(1)Gd4 tetrahedra, and edges with four equivalent O(2)Gd3Re tetrahedra. In the second O site, O(2) is bonded to one Gd(1), two equivalent Gd(2), and one Re(1) atom to form distorted OGd3Re tetrahedra that share corners with four equivalent O(1)Gd4 tetrahedra, corners with eight equivalent O(2)Gd3Re tetrahedra, edges with two equivalent O(2)Gd3Re tetrahedra, and edges with two equivalent O(1)Gd4 tetrahedra. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Gd(2) and two equivalent Re(1) atoms.
Gd3ReO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. All Gd(1)-O(1) bond lengths are 2.36 Å. All Gd(1)-O(2) bond lengths are 2.67 Å. In the second Gd site, Gd(2) is bonded to one O(3), two equivalent O(1), and four equivalent O(2) atoms to form distorted GdO7 pentagonal bipyramids that share corners with two equivalent Re(1)O6 octahedra, corners with three equivalent Gd(2)O7 pentagonal bipyramids, edges with two equivalent Re(1)O6 octahedra, and edges with two equivalent Gd(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 43°. The Gd(2)-O(3) bond length is 2.78 Å. There is one shorter (2.26 Å) and one longer (2.27 Å) Gd(2)-O(1) bond length. There are two shorter (2.35 Å) and two longer (2.39 Å) Gd(2)-O(2) bond lengths. Re(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form ReO6 octahedra that share corners with two equivalent Re(1)O6 octahedra, corners with four equivalent Gd(2)O7 pentagonal bipyramids, and edges with four equivalent Gd(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 22°. Both Re(1)-O(3) bond lengths are 1.91 Å. All Re(1)-O(2) bond lengths are 2.00 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Gd(1) and two equivalent Gd(2) atoms to form OGd4 tetrahedra that share corners with six equivalent O(1)Gd4 tetrahedra, corners with eight equivalent O(2)Gd3Re tetrahedra,  an edgeedge with one O(1)Gd4 tetrahedra, and edges with four equivalent O(2)Gd3Re tetrahedra. In the second O site, O(2) is bonded to one Gd(1), two equivalent Gd(2), and one Re(1) atom to form distorted OGd3Re tetrahedra that share corners with four equivalent O(1)Gd4 tetrahedra, corners with eight equivalent O(2)Gd3Re tetrahedra, edges with two equivalent O(2)Gd3Re tetrahedra, and edges with two equivalent O(1)Gd4 tetrahedra. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Gd(2) and two equivalent Re(1) atoms.