Bi2O3 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. In the second Bi site, Bi(2) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Bi(1) and two equivalent Bi(2) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the second O site, O(2) is bonded to two equivalent Bi(1) and two equivalent Bi(2) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Bi(2) and one O(3) atom.
Bi2O3 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. There is one shorter (2.20 Å) and one longer (2.72 Å) Bi(1)-O(1) bond length. There is one shorter (2.31 Å) and one longer (2.37 Å) Bi(1)-O(2) bond length. In the second Bi site, Bi(2) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. The Bi(2)-O(3) bond length is 2.36 Å. There is one shorter (2.35 Å) and one longer (2.40 Å) Bi(2)-O(1) bond length. There is one shorter (2.36 Å) and one longer (2.56 Å) Bi(2)-O(2) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Bi(1) and two equivalent Bi(2) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the second O site, O(2) is bonded to two equivalent Bi(1) and two equivalent Bi(2) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Bi(2) and one O(3) atom. The O(3)-O(3) bond length is 1.52 Å.