Ce2Ti2O7 crystallizes in the cubic Fd-3m space group. Ce(1) is bonded to two equivalent O(2) and six equivalent O(1) atoms to form distorted CeO8 hexagonal bipyramids that share edges with six equivalent Ce(1)O8 hexagonal bipyramids and edges with six equivalent Ti(1)O6 octahedra. Ti(1) is bonded to six equivalent O(1) atoms to form TiO6 octahedra that share corners with six equivalent Ti(1)O6 octahedra and edges with six equivalent Ce(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 48°. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ce(1) and two equivalent Ti(1) atoms to form distorted OCe2Ti2 tetrahedra that share corners with two equivalent O(2)Ce4 tetrahedra, corners with twelve equivalent O(1)Ce2Ti2 tetrahedra,  an edgeedge with one O(2)Ce4 tetrahedra, and edges with four equivalent O(1)Ce2Ti2 tetrahedra. In the second O site, O(2) is bonded to four equivalent Ce(1) atoms to form OCe4 tetrahedra that share corners with four equivalent O(2)Ce4 tetrahedra, corners with twelve equivalent O(1)Ce2Ti2 tetrahedra, and edges with six equivalent O(1)Ce2Ti2 tetrahedra.
Ce2Ti2O7 crystallizes in the cubic Fd-3m space group. Ce(1) is bonded to two equivalent O(2) and six equivalent O(1) atoms to form distorted CeO8 hexagonal bipyramids that share edges with six equivalent Ce(1)O8 hexagonal bipyramids and edges with six equivalent Ti(1)O6 octahedra. Both Ce(1)-O(2) bond lengths are 2.24 Å. All Ce(1)-O(1) bond lengths are 2.56 Å. Ti(1) is bonded to six equivalent O(1) atoms to form TiO6 octahedra that share corners with six equivalent Ti(1)O6 octahedra and edges with six equivalent Ce(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 48°. All Ti(1)-O(1) bond lengths are 2.00 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ce(1) and two equivalent Ti(1) atoms to form distorted OCe2Ti2 tetrahedra that share corners with two equivalent O(2)Ce4 tetrahedra, corners with twelve equivalent O(1)Ce2Ti2 tetrahedra,  an edgeedge with one O(2)Ce4 tetrahedra, and edges with four equivalent O(1)Ce2Ti2 tetrahedra. In the second O site, O(2) is bonded to four equivalent Ce(1) atoms to form OCe4 tetrahedra that share corners with four equivalent O(2)Ce4 tetrahedra, corners with twelve equivalent O(1)Ce2Ti2 tetrahedra, and edges with six equivalent O(1)Ce2Ti2 tetrahedra.