Bi2Sn2O7 crystallizes in the cubic Fd-3m space group. Sn(1) is bonded to six equivalent O(2) atoms to form SnO6 octahedra that share corners with six equivalent Sn(1)O6 octahedra and edges with six equivalent Bi(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 49°. Bi(1) is bonded to two equivalent O(1) and six equivalent O(2) atoms to form distorted BiO8 hexagonal bipyramids that share edges with six equivalent Bi(1)O8 hexagonal bipyramids and edges with six equivalent Sn(1)O6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Bi(1) atoms to form OBi4 tetrahedra that share corners with four equivalent O(1)Bi4 tetrahedra, corners with twelve equivalent O(2)Sn2Bi2 tetrahedra, and edges with six equivalent O(2)Sn2Bi2 tetrahedra. In the second O site, O(2) is bonded to two equivalent Sn(1) and two equivalent Bi(1) atoms to form distorted OSn2Bi2 tetrahedra that share corners with two equivalent O(1)Bi4 tetrahedra, corners with twelve equivalent O(2)Sn2Bi2 tetrahedra,  an edgeedge with one O(1)Bi4 tetrahedra, and edges with four equivalent O(2)Sn2Bi2 tetrahedra.
Bi2Sn2O7 crystallizes in the cubic Fd-3m space group. Sn(1) is bonded to six equivalent O(2) atoms to form SnO6 octahedra that share corners with six equivalent Sn(1)O6 octahedra and edges with six equivalent Bi(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 49°. All Sn(1)-O(2) bond lengths are 2.07 Å. Bi(1) is bonded to two equivalent O(1) and six equivalent O(2) atoms to form distorted BiO8 hexagonal bipyramids that share edges with six equivalent Bi(1)O8 hexagonal bipyramids and edges with six equivalent Sn(1)O6 octahedra. Both Bi(1)-O(1) bond lengths are 2.30 Å. All Bi(1)-O(2) bond lengths are 2.59 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Bi(1) atoms to form OBi4 tetrahedra that share corners with four equivalent O(1)Bi4 tetrahedra, corners with twelve equivalent O(2)Sn2Bi2 tetrahedra, and edges with six equivalent O(2)Sn2Bi2 tetrahedra. In the second O site, O(2) is bonded to two equivalent Sn(1) and two equivalent Bi(1) atoms to form distorted OSn2Bi2 tetrahedra that share corners with two equivalent O(1)Bi4 tetrahedra, corners with twelve equivalent O(2)Sn2Bi2 tetrahedra,  an edgeedge with one O(1)Bi4 tetrahedra, and edges with four equivalent O(2)Sn2Bi2 tetrahedra.