Bi3O7 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing BiO6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 34-35°. In the second Bi site, Bi(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form a mixture of corner and edge-sharing BiO6 octahedra. The corner-sharing octahedral tilt angles are 38°. There are four inequivalent O sites. In the first O site, O(4) is bonded in a bent 150 degrees geometry to two equivalent Bi(1) atoms. In the second O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Bi(2) and two equivalent Bi(1) atoms. In the third O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Bi(2) and two equivalent Bi(1) atoms. In the fourth O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent Bi(2) atoms.
Bi3O7 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing BiO6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 34-35°. There is one shorter (2.23 Å) and one longer (2.29 Å) Bi(1)-O(1) bond length. There is one shorter (2.23 Å) and one longer (2.32 Å) Bi(1)-O(2) bond length. Both Bi(1)-O(4) bond lengths are 2.11 Å. In the second Bi site, Bi(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form a mixture of corner and edge-sharing BiO6 octahedra. The corner-sharing octahedral tilt angles are 38°. Both Bi(2)-O(1) bond lengths are 2.21 Å. Both Bi(2)-O(2) bond lengths are 2.20 Å. There is one shorter (2.09 Å) and one longer (2.10 Å) Bi(2)-O(3) bond length. There are four inequivalent O sites. In the first O site, O(4) is bonded in a bent 150 degrees geometry to two equivalent Bi(1) atoms. In the second O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Bi(2) and two equivalent Bi(1) atoms. In the third O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Bi(2) and two equivalent Bi(1) atoms. In the fourth O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent Bi(2) atoms.