Ce2O3 crystallizes in the trigonal P-3m1 space group. Ce(1) is bonded in a 7-coordinate geometry to three equivalent O(2) and four equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Ce(1) atoms to form OCe4 tetrahedra that share corners with six equivalent O(2)Ce6 octahedra, corners with six equivalent O(1)Ce4 tetrahedra, edges with three equivalent O(2)Ce6 octahedra, and edges with three equivalent O(1)Ce4 tetrahedra. The corner-sharing octahedral tilt angles range from 16-58°. In the second O site, O(2) is bonded to six equivalent Ce(1) atoms to form OCe6 octahedra that share corners with twelve equivalent O(1)Ce4 tetrahedra, edges with six equivalent O(2)Ce6 octahedra, and edges with six equivalent O(1)Ce4 tetrahedra.
Ce2O3 crystallizes in the trigonal P-3m1 space group. Ce(1) is bonded in a 7-coordinate geometry to three equivalent O(2) and four equivalent O(1) atoms. All Ce(1)-O(2) bond lengths are 2.64 Å. There are three shorter (2.33 Å) and one longer (2.42 Å) Ce(1)-O(1) bond length. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Ce(1) atoms to form OCe4 tetrahedra that share corners with six equivalent O(2)Ce6 octahedra, corners with six equivalent O(1)Ce4 tetrahedra, edges with three equivalent O(2)Ce6 octahedra, and edges with three equivalent O(1)Ce4 tetrahedra. The corner-sharing octahedral tilt angles range from 16-58°. In the second O site, O(2) is bonded to six equivalent Ce(1) atoms to form OCe6 octahedra that share corners with twelve equivalent O(1)Ce4 tetrahedra, edges with six equivalent O(2)Ce6 octahedra, and edges with six equivalent O(1)Ce4 tetrahedra.