Y2Ti2O7 crystallizes in the cubic Fd-3m space group. Y(1) is bonded to two equivalent O(1) and six equivalent O(2) atoms to form distorted YO8 hexagonal bipyramids that share edges with six equivalent Y(1)O8 hexagonal bipyramids and edges with six equivalent Ti(1)O6 octahedra. Ti(1) is bonded to six equivalent O(2) atoms to form TiO6 octahedra that share corners with six equivalent Ti(1)O6 octahedra and edges with six equivalent Y(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 49°. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Y(1) atoms to form OY4 tetrahedra that share corners with four equivalent O(1)Y4 tetrahedra, corners with twelve equivalent O(2)Y2Ti2 tetrahedra, and edges with six equivalent O(2)Y2Ti2 tetrahedra. In the second O site, O(2) is bonded to two equivalent Y(1) and two equivalent Ti(1) atoms to form distorted OY2Ti2 tetrahedra that share corners with two equivalent O(1)Y4 tetrahedra, corners with twelve equivalent O(2)Y2Ti2 tetrahedra,  an edgeedge with one O(1)Y4 tetrahedra, and edges with four equivalent O(2)Y2Ti2 tetrahedra.
Y2Ti2O7 crystallizes in the cubic Fd-3m space group. Y(1) is bonded to two equivalent O(1) and six equivalent O(2) atoms to form distorted YO8 hexagonal bipyramids that share edges with six equivalent Y(1)O8 hexagonal bipyramids and edges with six equivalent Ti(1)O6 octahedra. Both Y(1)-O(1) bond lengths are 2.19 Å. All Y(1)-O(2) bond lengths are 2.48 Å. Ti(1) is bonded to six equivalent O(2) atoms to form TiO6 octahedra that share corners with six equivalent Ti(1)O6 octahedra and edges with six equivalent Y(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 49°. All Ti(1)-O(2) bond lengths are 1.96 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Y(1) atoms to form OY4 tetrahedra that share corners with four equivalent O(1)Y4 tetrahedra, corners with twelve equivalent O(2)Y2Ti2 tetrahedra, and edges with six equivalent O(2)Y2Ti2 tetrahedra. In the second O site, O(2) is bonded to two equivalent Y(1) and two equivalent Ti(1) atoms to form distorted OY2Ti2 tetrahedra that share corners with two equivalent O(1)Y4 tetrahedra, corners with twelve equivalent O(2)Y2Ti2 tetrahedra,  an edgeedge with one O(1)Y4 tetrahedra, and edges with four equivalent O(2)Y2Ti2 tetrahedra.