Gd3TaO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) 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 Ta(1)O6 octahedra, corners with three equivalent Gd(1)O7 pentagonal bipyramids, edges with two equivalent Ta(1)O6 octahedra, and edges with two equivalent Gd(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 40°. In the second Gd site, Gd(2) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. Ta(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Gd(1)O7 pentagonal bipyramids, and edges with four equivalent Gd(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 33°. 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 a mixture of corner and edge-sharing OGd4 tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Gd(2), two equivalent Gd(1), and one Ta(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Gd(1) and two equivalent Ta(1) atoms.
Gd3TaO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) 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 Ta(1)O6 octahedra, corners with three equivalent Gd(1)O7 pentagonal bipyramids, edges with two equivalent Ta(1)O6 octahedra, and edges with two equivalent Gd(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 40°. The Gd(1)-O(3) bond length is 2.67 Å. There is one shorter (2.25 Å) and one longer (2.29 Å) Gd(1)-O(1) bond length. There are two shorter (2.35 Å) and two longer (2.44 Å) Gd(1)-O(2) bond lengths. In the second Gd site, Gd(2) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. All Gd(2)-O(1) bond lengths are 2.38 Å. All Gd(2)-O(2) bond lengths are 2.70 Å. Ta(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Gd(1)O7 pentagonal bipyramids, and edges with four equivalent Gd(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 33°. Both Ta(1)-O(3) bond lengths are 1.98 Å. All Ta(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 a mixture of corner and edge-sharing OGd4 tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Gd(2), two equivalent Gd(1), and one Ta(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Gd(1) and two equivalent Ta(1) atoms.