Bi2O3 crystallizes in the monoclinic P2_1/c space group. There are four inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted corner-sharing BiO5 square pyramids. In the second Bi site, Bi(2) is bonded in a 6-coordinate geometry to one O(3), one O(4), one O(5), one O(6), and two equivalent O(2) atoms. In the third Bi site, Bi(3) is bonded to one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form distorted corner-sharing BiO5 square pyramids. In the fourth Bi site, Bi(4) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), one O(5), and one O(6) atom. There are six inequivalent O sites. In the first O site, O(5) is bonded in a 4-coordinate geometry to one Bi(1), one Bi(2), one Bi(3), and one Bi(4) atom. In the second O site, O(6) is bonded in a trigonal planar geometry to one Bi(1), one Bi(2), and one Bi(4) atom. In the third O site, O(1) is bonded in a distorted trigonal planar geometry to one Bi(4) and two equivalent Bi(3) atoms. In the fourth O site, O(2) is bonded in a trigonal non-coplanar geometry to one Bi(1) and two equivalent Bi(2) atoms. In the fifth O site, O(3) is bonded in a distorted tetrahedral geometry to one Bi(1), one Bi(2), one Bi(3), and one Bi(4) atom. In the sixth O site, O(4) is bonded in a 4-coordinate geometry to one Bi(1), one Bi(2), one Bi(3), and one Bi(4) atom.
Bi2O3 crystallizes in the monoclinic P2_1/c space group. There are four inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted corner-sharing BiO5 square pyramids. The Bi(1)-O(2) bond length is 2.13 Å. The Bi(1)-O(3) bond length is 2.54 Å. The Bi(1)-O(4) bond length is 2.26 Å. The Bi(1)-O(5) bond length is 2.46 Å. The Bi(1)-O(6) bond length is 2.16 Å. In the second Bi site, Bi(2) is bonded in a 6-coordinate geometry to one O(3), one O(4), one O(5), one O(6), and two equivalent O(2) atoms. The Bi(2)-O(3) bond length is 2.17 Å. The Bi(2)-O(4) bond length is 2.79 Å. The Bi(2)-O(5) bond length is 2.76 Å. The Bi(2)-O(6) bond length is 2.19 Å. There is one shorter (2.19 Å) and one longer (2.55 Å) Bi(2)-O(2) bond length. In the third Bi site, Bi(3) is bonded to one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form distorted corner-sharing BiO5 square pyramids. The Bi(3)-O(3) bond length is 2.13 Å. The Bi(3)-O(4) bond length is 2.41 Å. The Bi(3)-O(5) bond length is 2.25 Å. There is one shorter (2.32 Å) and one longer (2.40 Å) Bi(3)-O(1) bond length. In the fourth Bi site, Bi(4) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), one O(5), and one O(6) atom. The Bi(4)-O(1) bond length is 2.13 Å. The Bi(4)-O(3) bond length is 2.60 Å. The Bi(4)-O(4) bond length is 2.34 Å. The Bi(4)-O(5) bond length is 2.19 Å. The Bi(4)-O(6) bond length is 2.42 Å. There are six inequivalent O sites. In the first O site, O(5) is bonded in a 4-coordinate geometry to one Bi(1), one Bi(2), one Bi(3), and one Bi(4) atom. In the second O site, O(6) is bonded in a trigonal planar geometry to one Bi(1), one Bi(2), and one Bi(4) atom. In the third O site, O(1) is bonded in a distorted trigonal planar geometry to one Bi(4) and two equivalent Bi(3) atoms. In the fourth O site, O(2) is bonded in a trigonal non-coplanar geometry to one Bi(1) and two equivalent Bi(2) atoms. In the fifth O site, O(3) is bonded in a distorted tetrahedral geometry to one Bi(1), one Bi(2), one Bi(3), and one Bi(4) atom. In the sixth O site, O(4) is bonded in a 4-coordinate geometry to one Bi(1), one Bi(2), one Bi(3), and one Bi(4) atom.