Sr8Mn6Cu4S4O15 crystallizes in the monoclinic C2/m space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 11-coordinate geometry to one O(2); one O(3); one O(6); two equivalent O(4,5); two equivalent O(7,8); and four equivalent O(1) atoms. In the second Sr site, Sr(2) is bonded in a 4-coordinate geometry to four equivalent S(1); one O(2); one O(3); and two equivalent O(4,5) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1); one O(2); one O(3); and two equivalent O(4,5) atoms to form corner-sharing MnO5 square pyramids. In the second Mn site, Mn(2) is bonded to one O(6); two equivalent O(1); and two equivalent O(7,8) atoms to form corner-sharing MnO5 square pyramids. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to four equivalent S(1) atoms to form a mixture of edge and corner-sharing CuS4 tetrahedra. In the second Cu site, Cu(2) is bonded to four equivalent S(1) atoms to form a mixture of edge and corner-sharing CuS4 tetrahedra. S(1) is bonded in a 8-coordinate geometry to four equivalent Sr(2), two equivalent Cu(1), and two equivalent Cu(2) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to four equivalent Sr(1), one Mn(1), and one Mn(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms to form distorted corner-sharing OSr4Mn2 octahedra. The corner-sharing octahedral tilt angles are 58°. In the fourth O site, O(4,5) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms. In the fifth O site, O(6) is bonded in a distorted linear geometry to four equivalent Sr(1) and two equivalent Mn(2) atoms. In the sixth O site, O(7,8) is bonded to four equivalent Sr(1) and two equivalent Mn(2) atoms to form a mixture of distorted edge and corner-sharing OSr4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 3-58°.
Sr8Mn6Cu4S4O15 crystallizes in the monoclinic C2/m space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 11-coordinate geometry to one O(2); one O(3); one O(6); two equivalent O(4,5); two equivalent O(7,8); and four equivalent O(1) atoms. The Sr(1)-O(2) bond length is 3.06 Å. The Sr(1)-O(3) bond length is 2.80 Å. The Sr(1)-O(6) bond length is 2.78 Å. There is one shorter (2.93 Å) and one longer (2.94 Å) Sr(1)-O(4,5) bond length. Both Sr(1)-O(7,8) bond lengths are 2.81 Å. There are two shorter (2.68 Å) and two longer (2.93 Å) Sr(1)-O(1) bond lengths. In the second Sr site, Sr(2) is bonded in a 4-coordinate geometry to four equivalent S(1); one O(2); one O(3); and two equivalent O(4,5) atoms. There are a spread of Sr(2)-S(1) bond distances ranging from 3.17-3.20 Å. The Sr(2)-O(2) bond length is 2.48 Å. The Sr(2)-O(3) bond length is 2.60 Å. Both Sr(2)-O(4,5) bond lengths are 2.52 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1); one O(2); one O(3); and two equivalent O(4,5) atoms to form corner-sharing MnO5 square pyramids. The Mn(1)-O(1) bond length is 2.05 Å. The Mn(1)-O(2) bond length is 1.97 Å. The Mn(1)-O(3) bond length is 2.00 Å. Both Mn(1)-O(4,5) bond lengths are 2.00 Å. In the second Mn site, Mn(2) is bonded to one O(6); two equivalent O(1); and two equivalent O(7,8) atoms to form corner-sharing MnO5 square pyramids. The Mn(2)-O(6) bond length is 1.92 Å. Both Mn(2)-O(1) bond lengths are 1.92 Å. Both Mn(2)-O(7,8) bond lengths are 1.98 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to four equivalent S(1) atoms to form a mixture of edge and corner-sharing CuS4 tetrahedra. All Cu(1)-S(1) bond lengths are 2.41 Å. In the second Cu site, Cu(2) is bonded to four equivalent S(1) atoms to form a mixture of edge and corner-sharing CuS4 tetrahedra. There are two shorter (2.41 Å) and two longer (2.42 Å) Cu(2)-S(1) bond lengths. S(1) is bonded in a 8-coordinate geometry to four equivalent Sr(2), two equivalent Cu(1), and two equivalent Cu(2) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to four equivalent Sr(1), one Mn(1), and one Mn(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms to form distorted corner-sharing OSr4Mn2 octahedra. The corner-sharing octahedral tilt angles are 58°. In the fourth O site, O(4,5) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms. In the fifth O site, O(6) is bonded in a distorted linear geometry to four equivalent Sr(1) and two equivalent Mn(2) atoms. In the sixth O site, O(7,8) is bonded to four equivalent Sr(1) and two equivalent Mn(2) atoms to form a mixture of distorted edge and corner-sharing OSr4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 3-58°.