Mg4(BiO2)9 crystallizes in the triclinic P1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a see-saw-like geometry to one O(14), one O(16), one O(18), and one O(3) atom. In the second Mg site, Mg(2) is bonded in a distorted see-saw-like geometry to one O(18), one O(2), one O(4), and one O(6) atom. In the third Mg site, Mg(3) is bonded in a square co-planar geometry to one O(10), one O(15), one O(6), and one O(8) atom. In the fourth Mg site, Mg(4) is bonded in a 4-coordinate geometry to one O(1), one O(12), one O(13), and one O(15) atom. There are nine inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a rectangular see-saw-like geometry to one O(10), one O(16), one O(2), and one O(5) atom. In the second Bi site, Bi(2) is bonded to one O(15), one O(16), one O(17), and one O(4) atom to form distorted corner-sharing BiO4 tetrahedra. In the third Bi site, Bi(3) is bonded in a rectangular see-saw-like geometry to one O(17), one O(2), one O(3), and one O(7) atom. In the fourth Bi site, Bi(4) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(3), one O(4), and one O(5) atom. In the fifth Bi site, Bi(5) is bonded in a distorted rectangular see-saw-like geometry to one O(12), one O(6), one O(7), and one O(8) atom. In the sixth Bi site, Bi(6) is bonded in a 4-coordinate geometry to one O(11), one O(12), one O(13), and one O(5) atom. In the seventh Bi site, Bi(7) is bonded in a 6-coordinate geometry to one O(13), one O(14), one O(17), one O(18), one O(5), and one O(9) atom. In the eighth Bi site, Bi(8) is bonded in a distorted see-saw-like geometry to one O(11), one O(14), one O(7), and one O(9) atom. In the ninth Bi site, Bi(9) is bonded to one O(1), one O(11), one O(14), one O(17), and one O(8) atom to form distorted corner-sharing BiO5 square pyramids. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Mg(4), one Bi(4), and one Bi(9) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Mg(2), one Bi(1), and one Bi(3) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Bi(3), and one Bi(4) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(2), one Bi(2), and one Bi(4) atom. In the fifth O site, O(5) is bonded to one Bi(1), one Bi(4), one Bi(6), and one Bi(7) atom to form distorted corner-sharing OBi4 tetrahedra. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Mg(2), one Mg(3), and one Bi(5) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Bi(3), one Bi(5), and one Bi(8) atom. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Mg(3), one Bi(5), and one Bi(9) atom. In the ninth O site, O(9) is bonded in a distorted water-like geometry to one Bi(7) and one Bi(8) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Mg(3) and one Bi(1) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal non-coplanar geometry to one Bi(6), one Bi(8), and one Bi(9) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Mg(4), one Bi(5), and one Bi(6) atom. In the thirteenth O site, O(13) is bonded in a trigonal non-coplanar geometry to one Mg(4), one Bi(6), and one Bi(7) atom. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one Mg(1), one Bi(7), one Bi(8), and one Bi(9) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Mg(3), one Mg(4), and one Bi(2) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal planar geometry to one Mg(1), one Bi(1), and one Bi(2) atom. In the seventeenth O site, O(17) is bonded to one Bi(2), one Bi(3), one Bi(7), and one Bi(9) atom to form corner-sharing OBi4 tetrahedra. In the eighteenth O site, O(18) is bonded in a trigonal planar geometry to one Mg(1), one Mg(2), and one Bi(7) atom.
Mg4(BiO2)9 crystallizes in the triclinic P1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a see-saw-like geometry to one O(14), one O(16), one O(18), and one O(3) atom. The Mg(1)-O(14) bond length is 1.99 Å. The Mg(1)-O(16) bond length is 2.03 Å. The Mg(1)-O(18) bond length is 1.99 Å. The Mg(1)-O(3) bond length is 2.02 Å. In the second Mg site, Mg(2) is bonded in a distorted see-saw-like geometry to one O(18), one O(2), one O(4), and one O(6) atom. The Mg(2)-O(18) bond length is 1.99 Å. The Mg(2)-O(2) bond length is 2.03 Å. The Mg(2)-O(4) bond length is 2.00 Å. The Mg(2)-O(6) bond length is 1.95 Å. In the third Mg site, Mg(3) is bonded in a square co-planar geometry to one O(10), one O(15), one O(6), and one O(8) atom. The Mg(3)-O(10) bond length is 1.96 Å. The Mg(3)-O(15) bond length is 2.07 Å. The Mg(3)-O(6) bond length is 2.01 Å. The Mg(3)-O(8) bond length is 2.09 Å. In the fourth Mg site, Mg(4) is bonded in a 4-coordinate geometry to one O(1), one O(12), one O(13), and one O(15) atom. The Mg(4)-O(1) bond length is 2.22 Å. The Mg(4)-O(12) bond length is 2.01 Å. The Mg(4)-O(13) bond length is 2.43 Å. The Mg(4)-O(15) bond length is 2.01 Å. There are nine inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a rectangular see-saw-like geometry to one O(10), one O(16), one O(2), and one O(5) atom. The Bi(1)-O(10) bond length is 2.08 Å. The Bi(1)-O(16) bond length is 2.37 Å. The Bi(1)-O(2) bond length is 2.31 Å. The Bi(1)-O(5) bond length is 2.12 Å. In the second Bi site, Bi(2) is bonded to one O(15), one O(16), one O(17), and one O(4) atom to form distorted corner-sharing BiO4 tetrahedra. The Bi(2)-O(15) bond length is 2.30 Å. The Bi(2)-O(16) bond length is 2.19 Å. The Bi(2)-O(17) bond length is 2.17 Å. The Bi(2)-O(4) bond length is 2.10 Å. In the third Bi site, Bi(3) is bonded in a rectangular see-saw-like geometry to one O(17), one O(2), one O(3), and one O(7) atom. The Bi(3)-O(17) bond length is 2.49 Å. The Bi(3)-O(2) bond length is 2.14 Å. The Bi(3)-O(3) bond length is 2.42 Å. The Bi(3)-O(7) bond length is 2.19 Å. In the fourth Bi site, Bi(4) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(3), one O(4), and one O(5) atom. The Bi(4)-O(1) bond length is 2.21 Å. The Bi(4)-O(3) bond length is 2.13 Å. The Bi(4)-O(4) bond length is 2.47 Å. The Bi(4)-O(5) bond length is 2.30 Å. In the fifth Bi site, Bi(5) is bonded in a distorted rectangular see-saw-like geometry to one O(12), one O(6), one O(7), and one O(8) atom. The Bi(5)-O(12) bond length is 2.12 Å. The Bi(5)-O(6) bond length is 2.09 Å. The Bi(5)-O(7) bond length is 2.65 Å. The Bi(5)-O(8) bond length is 2.23 Å. In the sixth Bi site, Bi(6) is bonded in a 4-coordinate geometry to one O(11), one O(12), one O(13), and one O(5) atom. The Bi(6)-O(11) bond length is 2.15 Å. The Bi(6)-O(12) bond length is 2.18 Å. The Bi(6)-O(13) bond length is 2.14 Å. The Bi(6)-O(5) bond length is 2.73 Å. In the seventh Bi site, Bi(7) is bonded in a 6-coordinate geometry to one O(13), one O(14), one O(17), one O(18), one O(5), and one O(9) atom. The Bi(7)-O(13) bond length is 2.15 Å. The Bi(7)-O(14) bond length is 2.68 Å. The Bi(7)-O(17) bond length is 2.65 Å. The Bi(7)-O(18) bond length is 2.11 Å. The Bi(7)-O(5) bond length is 2.70 Å. The Bi(7)-O(9) bond length is 2.29 Å. In the eighth Bi site, Bi(8) is bonded in a distorted see-saw-like geometry to one O(11), one O(14), one O(7), and one O(9) atom. The Bi(8)-O(11) bond length is 2.19 Å. The Bi(8)-O(14) bond length is 2.38 Å. The Bi(8)-O(7) bond length is 2.25 Å. The Bi(8)-O(9) bond length is 2.13 Å. In the ninth Bi site, Bi(9) is bonded to one O(1), one O(11), one O(14), one O(17), and one O(8) atom to form distorted corner-sharing BiO5 square pyramids. The Bi(9)-O(1) bond length is 2.40 Å. The Bi(9)-O(11) bond length is 2.47 Å. The Bi(9)-O(14) bond length is 2.24 Å. The Bi(9)-O(17) bond length is 2.66 Å. The Bi(9)-O(8) bond length is 2.10 Å. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Mg(4), one Bi(4), and one Bi(9) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Mg(2), one Bi(1), and one Bi(3) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Bi(3), and one Bi(4) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(2), one Bi(2), and one Bi(4) atom. In the fifth O site, O(5) is bonded to one Bi(1), one Bi(4), one Bi(6), and one Bi(7) atom to form distorted corner-sharing OBi4 tetrahedra. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Mg(2), one Mg(3), and one Bi(5) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Bi(3), one Bi(5), and one Bi(8) atom. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Mg(3), one Bi(5), and one Bi(9) atom. In the ninth O site, O(9) is bonded in a distorted water-like geometry to one Bi(7) and one Bi(8) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Mg(3) and one Bi(1) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal non-coplanar geometry to one Bi(6), one Bi(8), and one Bi(9) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Mg(4), one Bi(5), and one Bi(6) atom. In the thirteenth O site, O(13) is bonded in a trigonal non-coplanar geometry to one Mg(4), one Bi(6), and one Bi(7) atom. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one Mg(1), one Bi(7), one Bi(8), and one Bi(9) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Mg(3), one Mg(4), and one Bi(2) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal planar geometry to one Mg(1), one Bi(1), and one Bi(2) atom. In the seventeenth O site, O(17) is bonded to one Bi(2), one Bi(3), one Bi(7), and one Bi(9) atom to form corner-sharing OBi4 tetrahedra. In the eighteenth O site, O(18) is bonded in a trigonal planar geometry to one Mg(1), one Mg(2), and one Bi(7) atom.