Ba8Y4(Cu4O9)3 crystallizes in the monoclinic C2/m space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one O(2), one O(4), one O(9), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. In the second Ba site, Ba(2) is bonded in a 9-coordinate geometry to one O(1), one O(4), one O(9), two equivalent O(5), two equivalent O(7), and two equivalent O(8) atoms. In the third Ba site, Ba(3) is bonded in a 10-coordinate geometry to one O(1), one O(10), one O(3), one O(9), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. In the fourth Ba site, Ba(4) is bonded in a 10-coordinate geometry to one O(10), one O(2), one O(3), one O(9), two equivalent O(5), two equivalent O(7), and two equivalent O(8) atoms. There are three inequivalent Y sites. In the first Y site, Y(1) is bonded in a body-centered cubic geometry to one O(1), one O(2), one O(3), one O(4), and four equivalent O(5) atoms. In the second Y site, Y(2) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(6) atoms. In the third Y site, Y(3) is bonded in a body-centered cubic geometry to two equivalent O(2), two equivalent O(4), and four equivalent O(6) atoms. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(1), one O(2), one O(5), one O(6), and one O(7) atom to form corner-sharing CuO5 square pyramids. In the second Cu site, Cu(2) is bonded to one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form distorted corner-sharing CuO5 square pyramids. In the third Cu site, Cu(3) is bonded in a square co-planar geometry to two equivalent O(7) and two equivalent O(9) atoms. In the fourth Cu site, Cu(4) is bonded in a T-shaped geometry to one O(10) and two equivalent O(8) atoms. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(3), one Y(1), one Y(2), and two equivalent Cu(1) atoms. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(4), one Y(1), one Y(3), and two equivalent Cu(1) atoms. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Ba(3), one Ba(4), one Y(1), one Y(2), and two equivalent Cu(2) atoms. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(2), one Y(1), one Y(3), and two equivalent Cu(2) atoms. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(4), two equivalent Y(1), one Cu(1), and one Cu(2) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(3), one Y(2), one Y(3), one Cu(1), and one Cu(2) atom. In the seventh O site, O(7) is bonded to one Ba(1), one Ba(2), one Ba(3), one Ba(4), one Cu(1), and one Cu(3) atom to form a mixture of distorted face, corner, and edge-sharing OBa4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-68°. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), one Ba(4), one Cu(2), and one Cu(4) atom. In the ninth O site, O(9) is bonded to one Ba(1), one Ba(2), one Ba(3), one Ba(4), and two equivalent Cu(3) atoms to form a mixture of distorted face, corner, and edge-sharing OBa4Cu2 octahedra. The corner-sharing octahedra are not tilted. In the tenth O site, O(10) is bonded to two equivalent Ba(3), two equivalent Ba(4), and two equivalent Cu(4) atoms to form a mixture of distorted corner and edge-sharing OBa4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 67-68°.
Ba8Y4(Cu4O9)3 crystallizes in the monoclinic C2/m space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one O(2), one O(4), one O(9), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. The Ba(1)-O(2) bond length is 2.93 Å. The Ba(1)-O(4) bond length is 3.03 Å. The Ba(1)-O(9) bond length is 2.91 Å. Both Ba(1)-O(6) bond lengths are 3.01 Å. Both Ba(1)-O(7) bond lengths are 2.74 Å. Both Ba(1)-O(8) bond lengths are 2.75 Å. In the second Ba site, Ba(2) is bonded in a 9-coordinate geometry to one O(1), one O(4), one O(9), two equivalent O(5), two equivalent O(7), and two equivalent O(8) atoms. The Ba(2)-O(1) bond length is 2.93 Å. The Ba(2)-O(4) bond length is 3.02 Å. The Ba(2)-O(9) bond length is 2.91 Å. Both Ba(2)-O(5) bond lengths are 3.01 Å. Both Ba(2)-O(7) bond lengths are 2.74 Å. Both Ba(2)-O(8) bond lengths are 2.75 Å. In the third Ba site, Ba(3) is bonded in a 10-coordinate geometry to one O(1), one O(10), one O(3), one O(9), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. The Ba(3)-O(1) bond length is 3.03 Å. The Ba(3)-O(10) bond length is 2.92 Å. The Ba(3)-O(3) bond length is 3.03 Å. The Ba(3)-O(9) bond length is 2.92 Å. Both Ba(3)-O(6) bond lengths are 3.07 Å. Both Ba(3)-O(7) bond lengths are 2.77 Å. Both Ba(3)-O(8) bond lengths are 2.88 Å. In the fourth Ba site, Ba(4) is bonded in a 10-coordinate geometry to one O(10), one O(2), one O(3), one O(9), two equivalent O(5), two equivalent O(7), and two equivalent O(8) atoms. The Ba(4)-O(10) bond length is 2.91 Å. The Ba(4)-O(2) bond length is 3.02 Å. The Ba(4)-O(3) bond length is 3.03 Å. The Ba(4)-O(9) bond length is 2.92 Å. Both Ba(4)-O(5) bond lengths are 3.07 Å. Both Ba(4)-O(7) bond lengths are 2.77 Å. Both Ba(4)-O(8) bond lengths are 2.88 Å. There are three inequivalent Y sites. In the first Y site, Y(1) is bonded in a body-centered cubic geometry to one O(1), one O(2), one O(3), one O(4), and four equivalent O(5) atoms. The Y(1)-O(1) bond length is 2.42 Å. The Y(1)-O(2) bond length is 2.41 Å. The Y(1)-O(3) bond length is 2.41 Å. The Y(1)-O(4) bond length is 2.41 Å. There are two shorter (2.43 Å) and two longer (2.45 Å) Y(1)-O(5) bond lengths. In the second Y site, Y(2) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(6) atoms. Both Y(2)-O(1) bond lengths are 2.41 Å. Both Y(2)-O(3) bond lengths are 2.41 Å. All Y(2)-O(6) bond lengths are 2.44 Å. In the third Y site, Y(3) is bonded in a body-centered cubic geometry to two equivalent O(2), two equivalent O(4), and four equivalent O(6) atoms. Both Y(3)-O(2) bond lengths are 2.41 Å. Both Y(3)-O(4) bond lengths are 2.40 Å. All Y(3)-O(6) bond lengths are 2.44 Å. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(1), one O(2), one O(5), one O(6), and one O(7) atom to form corner-sharing CuO5 square pyramids. The Cu(1)-O(1) bond length is 1.99 Å. The Cu(1)-O(2) bond length is 1.99 Å. The Cu(1)-O(5) bond length is 1.95 Å. The Cu(1)-O(6) bond length is 1.95 Å. The Cu(1)-O(7) bond length is 2.37 Å. In the second Cu site, Cu(2) is bonded to one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form distorted corner-sharing CuO5 square pyramids. The Cu(2)-O(3) bond length is 1.99 Å. The Cu(2)-O(4) bond length is 1.99 Å. The Cu(2)-O(5) bond length is 1.95 Å. The Cu(2)-O(6) bond length is 1.95 Å. The Cu(2)-O(8) bond length is 2.45 Å. In the third Cu site, Cu(3) is bonded in a square co-planar geometry to two equivalent O(7) and two equivalent O(9) atoms. Both Cu(3)-O(7) bond lengths are 1.89 Å. Both Cu(3)-O(9) bond lengths are 1.97 Å. In the fourth Cu site, Cu(4) is bonded in a T-shaped geometry to one O(10) and two equivalent O(8) atoms. The Cu(4)-O(10) bond length is 1.89 Å. Both Cu(4)-O(8) bond lengths are 1.83 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(3), one Y(1), one Y(2), and two equivalent Cu(1) atoms. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(4), one Y(1), one Y(3), and two equivalent Cu(1) atoms. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Ba(3), one Ba(4), one Y(1), one Y(2), and two equivalent Cu(2) atoms. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(2), one Y(1), one Y(3), and two equivalent Cu(2) atoms. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(4), two equivalent Y(1), one Cu(1), and one Cu(2) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(3), one Y(2), one Y(3), one Cu(1), and one Cu(2) atom. In the seventh O site, O(7) is bonded to one Ba(1), one Ba(2), one Ba(3), one Ba(4), one Cu(1), and one Cu(3) atom to form a mixture of distorted face, corner, and edge-sharing OBa4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-68°. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), one Ba(4), one Cu(2), and one Cu(4) atom. In the ninth O site, O(9) is bonded to one Ba(1), one Ba(2), one Ba(3), one Ba(4), and two equivalent Cu(3) atoms to form a mixture of distorted face, corner, and edge-sharing OBa4Cu2 octahedra. The corner-sharing octahedra are not tilted. In the tenth O site, O(10) is bonded to two equivalent Ba(3), two equivalent Ba(4), and two equivalent Cu(4) atoms to form a mixture of distorted corner and edge-sharing OBa4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 67-68°.