Gd2O3 crystallizes in the trigonal P-3m1 space group. Gd(1) is bonded in a 7-coordinate geometry to three equivalent O(1) and four equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to six equivalent Gd(1) atoms to form OGd6 octahedra that share corners with twelve equivalent O(2)Gd4 tetrahedra, edges with six equivalent O(1)Gd6 octahedra, and edges with six equivalent O(2)Gd4 tetrahedra. In the second O site, O(2) is bonded to four equivalent Gd(1) atoms to form OGd4 tetrahedra that share corners with six equivalent O(1)Gd6 octahedra, corners with six equivalent O(2)Gd4 tetrahedra, edges with three equivalent O(1)Gd6 octahedra, and edges with three equivalent O(2)Gd4 tetrahedra. The corner-sharing octahedral tilt angles range from 18-56°.
Gd2O3 crystallizes in the trigonal P-3m1 space group. Gd(1) is bonded in a 7-coordinate geometry to three equivalent O(1) and four equivalent O(2) atoms. All Gd(1)-O(1) bond lengths are 2.60 Å. There are three shorter (2.24 Å) and one longer (2.34 Å) Gd(1)-O(2) bond length. There are two inequivalent O sites. In the first O site, O(1) is bonded to six equivalent Gd(1) atoms to form OGd6 octahedra that share corners with twelve equivalent O(2)Gd4 tetrahedra, edges with six equivalent O(1)Gd6 octahedra, and edges with six equivalent O(2)Gd4 tetrahedra. In the second O site, O(2) is bonded to four equivalent Gd(1) atoms to form OGd4 tetrahedra that share corners with six equivalent O(1)Gd6 octahedra, corners with six equivalent O(2)Gd4 tetrahedra, edges with three equivalent O(1)Gd6 octahedra, and edges with three equivalent O(2)Gd4 tetrahedra. The corner-sharing octahedral tilt angles range from 18-56°.