Bi4O5Br2 crystallizes in the monoclinic P2_1 space group. There are eight inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 3-coordinate geometry to one O(1), one O(2), one O(3), and one Br(1) atom. In the second Bi site, Bi(2) is bonded in a 3-coordinate geometry to one O(2), one O(3), one O(4), one Br(3), and two equivalent Br(1) atoms. In the third Bi site, Bi(3) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(5), one O(6), one O(9), and one Br(4) atom. In the fourth Bi site, Bi(4) is bonded in a 6-coordinate geometry to one O(1), one O(3), two equivalent O(5), two equivalent O(6), and one Br(4) atom. In the fifth Bi site, Bi(5) is bonded in a 6-coordinate geometry to one O(10), one O(2), one O(4), one O(5), one O(6), and one O(9) atom. In the sixth Bi site, Bi(6) is bonded in a 6-coordinate geometry to one O(10), one O(4), one O(7), one O(8), one O(9), and one Br(2) atom. In the seventh Bi site, Bi(7) is bonded in a 4-coordinate geometry to two equivalent O(7), two equivalent O(8), one Br(3), and two equivalent Br(1) atoms. In the eighth Bi site, Bi(8) is bonded in a 4-coordinate geometry to one O(10), one O(7), one O(8), one O(9), one Br(1), and one Br(4) atom. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Bi(1), one Bi(3), and one Bi(4) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Bi(1), one Bi(2), and one Bi(5) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Bi(1), one Bi(2), and one Bi(4) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Bi(2), one Bi(5), and one Bi(6) atom. In the fifth O site, O(5) is bonded to one Bi(3), one Bi(5), and two equivalent Bi(4) atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the sixth O site, O(6) is bonded to one Bi(3), one Bi(5), and two equivalent Bi(4) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the seventh O site, O(7) is bonded to one Bi(6), one Bi(8), and two equivalent Bi(7) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the eighth O site, O(8) is bonded to one Bi(6), one Bi(8), and two equivalent Bi(7) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the ninth O site, O(9) is bonded to one Bi(3), one Bi(5), one Bi(6), and one Bi(8) atom to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the tenth O site, O(10) is bonded to one Bi(3), one Bi(5), one Bi(6), and one Bi(8) atom to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. There are four inequivalent Br sites. In the first Br site, Br(1) is bonded in a 6-coordinate geometry to one Bi(1), one Bi(8), two equivalent Bi(2), and two equivalent Bi(7) atoms. In the second Br site, Br(2) is bonded in a 1-coordinate geometry to one Bi(6) atom. In the third Br site, Br(3) is bonded in a 2-coordinate geometry to one Bi(2) and one Bi(7) atom. In the fourth Br site, Br(4) is bonded in a 3-coordinate geometry to one Bi(3), one Bi(4), and one Bi(8) atom.
Bi4O5Br2 crystallizes in the monoclinic P2_1 space group. There are eight inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 3-coordinate geometry to one O(1), one O(2), one O(3), and one Br(1) atom. The Bi(1)-O(1) bond length is 2.11 Å. The Bi(1)-O(2) bond length is 2.10 Å. The Bi(1)-O(3) bond length is 2.13 Å. The Bi(1)-Br(1) bond length is 3.35 Å. In the second Bi site, Bi(2) is bonded in a 3-coordinate geometry to one O(2), one O(3), one O(4), one Br(3), and two equivalent Br(1) atoms. The Bi(2)-O(2) bond length is 2.12 Å. The Bi(2)-O(3) bond length is 2.12 Å. The Bi(2)-O(4) bond length is 2.10 Å. The Bi(2)-Br(3) bond length is 3.34 Å. There is one shorter (3.43 Å) and one longer (3.47 Å) Bi(2)-Br(1) bond length. In the third Bi site, Bi(3) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(5), one O(6), one O(9), and one Br(4) atom. The Bi(3)-O(1) bond length is 2.26 Å. The Bi(3)-O(10) bond length is 2.61 Å. The Bi(3)-O(5) bond length is 2.25 Å. The Bi(3)-O(6) bond length is 2.20 Å. The Bi(3)-O(9) bond length is 2.46 Å. The Bi(3)-Br(4) bond length is 3.11 Å. In the fourth Bi site, Bi(4) is bonded in a 6-coordinate geometry to one O(1), one O(3), two equivalent O(5), two equivalent O(6), and one Br(4) atom. The Bi(4)-O(1) bond length is 2.29 Å. The Bi(4)-O(3) bond length is 2.52 Å. There is one shorter (2.33 Å) and one longer (2.63 Å) Bi(4)-O(5) bond length. There is one shorter (2.19 Å) and one longer (2.66 Å) Bi(4)-O(6) bond length. The Bi(4)-Br(4) bond length is 3.26 Å. In the fifth Bi site, Bi(5) is bonded in a 6-coordinate geometry to one O(10), one O(2), one O(4), one O(5), one O(6), and one O(9) atom. The Bi(5)-O(10) bond length is 2.31 Å. The Bi(5)-O(2) bond length is 2.53 Å. The Bi(5)-O(4) bond length is 2.38 Å. The Bi(5)-O(5) bond length is 2.18 Å. The Bi(5)-O(6) bond length is 2.50 Å. The Bi(5)-O(9) bond length is 2.67 Å. In the sixth Bi site, Bi(6) is bonded in a 6-coordinate geometry to one O(10), one O(4), one O(7), one O(8), one O(9), and one Br(2) atom. The Bi(6)-O(10) bond length is 2.25 Å. The Bi(6)-O(4) bond length is 2.21 Å. The Bi(6)-O(7) bond length is 2.60 Å. The Bi(6)-O(8) bond length is 2.64 Å. The Bi(6)-O(9) bond length is 2.18 Å. The Bi(6)-Br(2) bond length is 3.14 Å. In the seventh Bi site, Bi(7) is bonded in a 4-coordinate geometry to two equivalent O(7), two equivalent O(8), one Br(3), and two equivalent Br(1) atoms. Both Bi(7)-O(7) bond lengths are 2.25 Å. There is one shorter (2.26 Å) and one longer (2.27 Å) Bi(7)-O(8) bond length. The Bi(7)-Br(3) bond length is 3.36 Å. There is one shorter (3.44 Å) and one longer (3.48 Å) Bi(7)-Br(1) bond length. In the eighth Bi site, Bi(8) is bonded in a 4-coordinate geometry to one O(10), one O(7), one O(8), one O(9), one Br(1), and one Br(4) atom. The Bi(8)-O(10) bond length is 2.21 Å. The Bi(8)-O(7) bond length is 2.31 Å. The Bi(8)-O(8) bond length is 2.28 Å. The Bi(8)-O(9) bond length is 2.20 Å. The Bi(8)-Br(1) bond length is 3.46 Å. The Bi(8)-Br(4) bond length is 3.41 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Bi(1), one Bi(3), and one Bi(4) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Bi(1), one Bi(2), and one Bi(5) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Bi(1), one Bi(2), and one Bi(4) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Bi(2), one Bi(5), and one Bi(6) atom. In the fifth O site, O(5) is bonded to one Bi(3), one Bi(5), and two equivalent Bi(4) atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the sixth O site, O(6) is bonded to one Bi(3), one Bi(5), and two equivalent Bi(4) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the seventh O site, O(7) is bonded to one Bi(6), one Bi(8), and two equivalent Bi(7) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the eighth O site, O(8) is bonded to one Bi(6), one Bi(8), and two equivalent Bi(7) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the ninth O site, O(9) is bonded to one Bi(3), one Bi(5), one Bi(6), and one Bi(8) atom to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the tenth O site, O(10) is bonded to one Bi(3), one Bi(5), one Bi(6), and one Bi(8) atom to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. There are four inequivalent Br sites. In the first Br site, Br(1) is bonded in a 6-coordinate geometry to one Bi(1), one Bi(8), two equivalent Bi(2), and two equivalent Bi(7) atoms. In the second Br site, Br(2) is bonded in a 1-coordinate geometry to one Bi(6) atom. In the third Br site, Br(3) is bonded in a 2-coordinate geometry to one Bi(2) and one Bi(7) atom. In the fourth Br site, Br(4) is bonded in a 3-coordinate geometry to one Bi(3), one Bi(4), and one Bi(8) atom.