Ca2GdTaO6 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), three equivalent O(1), and three equivalent O(3) atoms. Gd(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form GdO6 octahedra that share corners with six equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-40°. Ta(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form TaO6 octahedra that share corners with six equivalent Gd(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-40°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to three equivalent Ca(1), one Gd(1), and one Ta(1) atom. In the second O site, O(2) is bonded to two equivalent Ca(1), one Gd(1), and one Ta(1) atom to form distorted corner-sharing OCa2GdTa tetrahedra. In the third O site, O(3) is bonded in a 4-coordinate geometry to three equivalent Ca(1), one Gd(1), and one Ta(1) atom.
Ca2GdTaO6 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), three equivalent O(1), and three equivalent O(3) atoms. There is one shorter (2.34 Å) and one longer (2.43 Å) Ca(1)-O(2) bond length. There are a spread of Ca(1)-O(1) bond distances ranging from 2.35-2.84 Å. There are a spread of Ca(1)-O(3) bond distances ranging from 2.38-3.03 Å. Gd(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form GdO6 octahedra that share corners with six equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-40°. Both Gd(1)-O(1) bond lengths are 2.28 Å. Both Gd(1)-O(2) bond lengths are 2.32 Å. Both Gd(1)-O(3) bond lengths are 2.31 Å. Ta(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form TaO6 octahedra that share corners with six equivalent Gd(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-40°. Both Ta(1)-O(1) bond lengths are 2.00 Å. Both Ta(1)-O(2) bond lengths are 2.02 Å. Both Ta(1)-O(3) bond lengths are 2.03 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to three equivalent Ca(1), one Gd(1), and one Ta(1) atom. In the second O site, O(2) is bonded to two equivalent Ca(1), one Gd(1), and one Ta(1) atom to form distorted corner-sharing OCa2GdTa tetrahedra. In the third O site, O(3) is bonded in a 4-coordinate geometry to three equivalent Ca(1), one Gd(1), and one Ta(1) atom.