Sr8MgMn6O20 is Orthorhombic Perovskite-derived structured and crystallizes in the triclinic P1 space group. There are eight inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to one O(11), one O(14), one O(15), one O(2), one O(3), one O(8), and two equivalent O(18) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one O(1), one O(12), one O(13), one O(16), one O(4), one O(7), and two equivalent O(19) atoms. In the third Sr site, Sr(3) is bonded in a 9-coordinate geometry to one O(10), one O(2), one O(20), one O(3), one O(5), one O(6), one O(9), and two equivalent O(14) atoms. In the fourth Sr site, Sr(4) is bonded in a 9-coordinate geometry to one O(1), one O(10), one O(17), one O(19), one O(5), one O(6), one O(9), and two equivalent O(13) atoms. In the fifth Sr site, Sr(5) is bonded in a 9-coordinate geometry to one O(1), one O(10), one O(13), one O(4), one O(5), one O(6), one O(9), and two equivalent O(17) atoms. In the sixth Sr site, Sr(6) is bonded in a 10-coordinate geometry to one O(10), one O(14), one O(15), one O(2), one O(3), one O(5), one O(6), one O(9), and two equivalent O(20) atoms. In the seventh Sr site, Sr(7) is bonded in a 9-coordinate geometry to one O(11), one O(12), one O(18), one O(2), one O(20), one O(3), one O(8), and two equivalent O(15) atoms. In the eighth Sr site, Sr(8) is bonded in a 9-coordinate geometry to one O(1), one O(11), one O(12), one O(19), one O(4), one O(7), one O(8), and two equivalent O(16) atoms. Mg(1) is bonded in a 5-coordinate geometry to one O(11), one O(12), one O(16), one O(18), and one O(8) atom. There are six inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(13), one O(17), one O(4), one O(6), and one O(9) atom to form face-sharing MnO6 octahedra. In the second Mn site, Mn(2) is bonded to one O(10), one O(14), one O(2), one O(20), one O(3), and one O(5) atom to form a mixture of face and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 4-7°. In the third Mn site, Mn(3) is bonded to one O(11), one O(15), one O(18), one O(2), one O(3), and one O(8) atom to form a mixture of face and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 4-7°. In the fourth Mn site, Mn(4) is bonded in a 4-coordinate geometry to one O(1), one O(16), one O(19), one O(4), and one O(7) atom. In the fifth Mn site, Mn(5) is bonded to one O(10), one O(17), one O(20), one O(5), one O(6), and one O(9) atom to form face-sharing MnO6 octahedra. In the sixth Mn site, Mn(6) is bonded to one O(11), one O(12), one O(15), one O(16), one O(7), and one O(8) atom to form distorted face-sharing MnO6 octahedra. There are twenty inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Sr(2), one Sr(4), one Sr(5), one Sr(8), one Mn(1), and one Mn(4) atom. In the second O site, O(2) is bonded in a distorted linear geometry to one Sr(1), one Sr(3), one Sr(6), one Sr(7), one Mn(2), and one Mn(3) atom. In the third O site, O(3) is bonded in a distorted linear geometry to one Sr(1), one Sr(3), one Sr(6), one Sr(7), one Mn(2), and one Mn(3) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Sr(2), one Sr(5), one Sr(8), one Mn(1), and one Mn(4) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Sr(3), one Sr(4), one Sr(5), one Sr(6), one Mn(2), and one Mn(5) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Sr(3), one Sr(4), one Sr(5), one Sr(6), one Mn(1), and one Mn(5) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Sr(2), one Sr(8), one Mn(4), and one Mn(6) atom. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(7), one Sr(8), one Mg(1), one Mn(3), and one Mn(6) atom. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Sr(3), one Sr(4), one Sr(5), one Sr(6), one Mn(1), and one Mn(5) atom. In the tenth O site, O(10) is bonded in a 6-coordinate geometry to one Sr(3), one Sr(4), one Sr(5), one Sr(6), one Mn(2), and one Mn(5) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(7), one Sr(8), one Mg(1), one Mn(3), and one Mn(6) atom. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to one Sr(2), one Sr(7), one Sr(8), one Mg(1), and one Mn(6) atom. In the thirteenth O site, O(13) is bonded in a 5-coordinate geometry to one Sr(2), one Sr(5), two equivalent Sr(4), and one Mn(1) atom. In the fourteenth O site, O(14) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(6), two equivalent Sr(3), and one Mn(2) atom. In the fifteenth O site, O(15) is bonded to one Sr(1), one Sr(6), two equivalent Sr(7), one Mn(3), and one Mn(6) atom to form a mixture of distorted corner and edge-sharing OSr4Mn2 octahedra. The corner-sharing octahedral tilt angles are 10°. In the sixteenth O site, O(16) is bonded in a 6-coordinate geometry to one Sr(2), two equivalent Sr(8), one Mg(1), one Mn(4), and one Mn(6) atom. In the seventeenth O site, O(17) is bonded to one Sr(4), two equivalent Sr(5), one Mn(1), and one Mn(5) atom to form distorted OSr3Mn2 square pyramids that share  a cornercorner with one O(20)Sr4Mn2 octahedra and corners with two equivalent O(17)Sr3Mn2 square pyramids. The corner-sharing octahedral tilt angles are 2°. In the eighteenth O site, O(18) is bonded in a 5-coordinate geometry to one Sr(7), two equivalent Sr(1), one Mg(1), and one Mn(3) atom. In the nineteenth O site, O(19) is bonded in a 5-coordinate geometry to one Sr(4), one Sr(8), two equivalent Sr(2), and one Mn(4) atom. In the twentieth O site, O(20) is bonded to one Sr(3), one Sr(7), two equivalent Sr(6), one Mn(2), and one Mn(5) atom to form distorted OSr4Mn2 octahedra that share corners with two equivalent O(20)Sr4Mn2 octahedra,  a cornercorner with one O(17)Sr3Mn2 square pyramid, and edges with two equivalent O(15)Sr4Mn2 octahedra. The corner-sharing octahedral tilt angles are 6°.
Sr8MgMn6O20 is Orthorhombic Perovskite-derived structured and crystallizes in the triclinic P1 space group. There are eight inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to one O(11), one O(14), one O(15), one O(2), one O(3), one O(8), and two equivalent O(18) atoms. The Sr(1)-O(11) bond length is 2.70 Å. The Sr(1)-O(14) bond length is 2.61 Å. The Sr(1)-O(15) bond length is 2.42 Å. The Sr(1)-O(2) bond length is 2.62 Å. The Sr(1)-O(3) bond length is 2.64 Å. The Sr(1)-O(8) bond length is 2.71 Å. There is one shorter (2.73 Å) and one longer (2.83 Å) Sr(1)-O(18) bond length. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one O(1), one O(12), one O(13), one O(16), one O(4), one O(7), and two equivalent O(19) atoms. The Sr(2)-O(1) bond length is 2.67 Å. The Sr(2)-O(12) bond length is 2.75 Å. The Sr(2)-O(13) bond length is 2.44 Å. The Sr(2)-O(16) bond length is 2.44 Å. The Sr(2)-O(4) bond length is 2.69 Å. The Sr(2)-O(7) bond length is 2.61 Å. There is one shorter (2.77 Å) and one longer (2.84 Å) Sr(2)-O(19) bond length. In the third Sr site, Sr(3) is bonded in a 9-coordinate geometry to one O(10), one O(2), one O(20), one O(3), one O(5), one O(6), one O(9), and two equivalent O(14) atoms. The Sr(3)-O(10) bond length is 2.50 Å. The Sr(3)-O(2) bond length is 2.93 Å. The Sr(3)-O(20) bond length is 2.49 Å. The Sr(3)-O(3) bond length is 3.00 Å. The Sr(3)-O(5) bond length is 2.56 Å. The Sr(3)-O(6) bond length is 2.77 Å. The Sr(3)-O(9) bond length is 2.74 Å. There is one shorter (2.85 Å) and one longer (2.89 Å) Sr(3)-O(14) bond length. In the fourth Sr site, Sr(4) is bonded in a 9-coordinate geometry to one O(1), one O(10), one O(17), one O(19), one O(5), one O(6), one O(9), and two equivalent O(13) atoms. The Sr(4)-O(1) bond length is 2.90 Å. The Sr(4)-O(10) bond length is 2.92 Å. The Sr(4)-O(17) bond length is 2.44 Å. The Sr(4)-O(19) bond length is 2.72 Å. The Sr(4)-O(5) bond length is 2.86 Å. The Sr(4)-O(6) bond length is 2.58 Å. The Sr(4)-O(9) bond length is 2.63 Å. There is one shorter (2.82 Å) and one longer (2.83 Å) Sr(4)-O(13) bond length. In the fifth Sr site, Sr(5) is bonded in a 9-coordinate geometry to one O(1), one O(10), one O(13), one O(4), one O(5), one O(6), one O(9), and two equivalent O(17) atoms. The Sr(5)-O(1) bond length is 2.61 Å. The Sr(5)-O(10) bond length is 3.01 Å. The Sr(5)-O(13) bond length is 2.44 Å. The Sr(5)-O(4) bond length is 2.77 Å. The Sr(5)-O(5) bond length is 2.95 Å. The Sr(5)-O(6) bond length is 2.61 Å. The Sr(5)-O(9) bond length is 2.55 Å. There is one shorter (2.76 Å) and one longer (2.78 Å) Sr(5)-O(17) bond length. In the sixth Sr site, Sr(6) is bonded in a 10-coordinate geometry to one O(10), one O(14), one O(15), one O(2), one O(3), one O(5), one O(6), one O(9), and two equivalent O(20) atoms. The Sr(6)-O(10) bond length is 2.65 Å. The Sr(6)-O(14) bond length is 2.38 Å. The Sr(6)-O(15) bond length is 2.77 Å. The Sr(6)-O(2) bond length is 2.63 Å. The Sr(6)-O(3) bond length is 2.66 Å. The Sr(6)-O(5) bond length is 2.64 Å. The Sr(6)-O(6) bond length is 3.08 Å. The Sr(6)-O(9) bond length is 3.00 Å. There is one shorter (2.75 Å) and one longer (2.79 Å) Sr(6)-O(20) bond length. In the seventh Sr site, Sr(7) is bonded in a 9-coordinate geometry to one O(11), one O(12), one O(18), one O(2), one O(20), one O(3), one O(8), and two equivalent O(15) atoms. The Sr(7)-O(11) bond length is 2.54 Å. The Sr(7)-O(12) bond length is 3.05 Å. The Sr(7)-O(18) bond length is 2.43 Å. The Sr(7)-O(2) bond length is 2.73 Å. The Sr(7)-O(20) bond length is 2.94 Å. The Sr(7)-O(3) bond length is 2.65 Å. The Sr(7)-O(8) bond length is 2.60 Å. There is one shorter (2.74 Å) and one longer (2.82 Å) Sr(7)-O(15) bond length. In the eighth Sr site, Sr(8) is bonded in a 9-coordinate geometry to one O(1), one O(11), one O(12), one O(19), one O(4), one O(7), one O(8), and two equivalent O(16) atoms. The Sr(8)-O(1) bond length is 2.78 Å. The Sr(8)-O(11) bond length is 3.28 Å. The Sr(8)-O(12) bond length is 3.18 Å. The Sr(8)-O(19) bond length is 2.51 Å. The Sr(8)-O(4) bond length is 2.68 Å. The Sr(8)-O(7) bond length is 2.71 Å. The Sr(8)-O(8) bond length is 3.06 Å. There is one shorter (2.78 Å) and one longer (2.87 Å) Sr(8)-O(16) bond length. Mg(1) is bonded in a 5-coordinate geometry to one O(11), one O(12), one O(16), one O(18), and one O(8) atom. The Mg(1)-O(11) bond length is 2.32 Å. The Mg(1)-O(12) bond length is 2.15 Å. The Mg(1)-O(16) bond length is 2.13 Å. The Mg(1)-O(18) bond length is 2.06 Å. The Mg(1)-O(8) bond length is 2.05 Å. There are six inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(13), one O(17), one O(4), one O(6), and one O(9) atom to form face-sharing MnO6 octahedra. The Mn(1)-O(1) bond length is 1.90 Å. The Mn(1)-O(13) bond length is 1.88 Å. The Mn(1)-O(17) bond length is 1.97 Å. The Mn(1)-O(4) bond length is 1.93 Å. The Mn(1)-O(6) bond length is 2.00 Å. The Mn(1)-O(9) bond length is 2.08 Å. In the second Mn site, Mn(2) is bonded to one O(10), one O(14), one O(2), one O(20), one O(3), and one O(5) atom to form a mixture of face and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 4-7°. The Mn(2)-O(10) bond length is 1.96 Å. The Mn(2)-O(14) bond length is 1.83 Å. The Mn(2)-O(2) bond length is 1.91 Å. The Mn(2)-O(20) bond length is 2.05 Å. The Mn(2)-O(3) bond length is 1.90 Å. The Mn(2)-O(5) bond length is 1.97 Å. In the third Mn site, Mn(3) is bonded to one O(11), one O(15), one O(18), one O(2), one O(3), and one O(8) atom to form a mixture of face and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 4-7°. The Mn(3)-O(11) bond length is 1.93 Å. The Mn(3)-O(15) bond length is 1.96 Å. The Mn(3)-O(18) bond length is 1.94 Å. The Mn(3)-O(2) bond length is 1.92 Å. The Mn(3)-O(3) bond length is 1.92 Å. The Mn(3)-O(8) bond length is 1.95 Å. In the fourth Mn site, Mn(4) is bonded in a 4-coordinate geometry to one O(1), one O(16), one O(19), one O(4), and one O(7) atom. The Mn(4)-O(1) bond length is 2.04 Å. The Mn(4)-O(16) bond length is 2.68 Å. The Mn(4)-O(19) bond length is 1.87 Å. The Mn(4)-O(4) bond length is 1.92 Å. The Mn(4)-O(7) bond length is 1.93 Å. In the fifth Mn site, Mn(5) is bonded to one O(10), one O(17), one O(20), one O(5), one O(6), and one O(9) atom to form face-sharing MnO6 octahedra. The Mn(5)-O(10) bond length is 1.93 Å. The Mn(5)-O(17) bond length is 1.90 Å. The Mn(5)-O(20) bond length is 1.94 Å. The Mn(5)-O(5) bond length is 1.95 Å. The Mn(5)-O(6) bond length is 1.91 Å. The Mn(5)-O(9) bond length is 1.92 Å. In the sixth Mn site, Mn(6) is bonded to one O(11), one O(12), one O(15), one O(16), one O(7), and one O(8) atom to form distorted face-sharing MnO6 octahedra. The Mn(6)-O(11) bond length is 1.98 Å. The Mn(6)-O(12) bond length is 2.01 Å. The Mn(6)-O(15) bond length is 2.35 Å. The Mn(6)-O(16) bond length is 2.27 Å. The Mn(6)-O(7) bond length is 1.92 Å. The Mn(6)-O(8) bond length is 2.17 Å. There are twenty inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Sr(2), one Sr(4), one Sr(5), one Sr(8), one Mn(1), and one Mn(4) atom. In the second O site, O(2) is bonded in a distorted linear geometry to one Sr(1), one Sr(3), one Sr(6), one Sr(7), one Mn(2), and one Mn(3) atom. In the third O site, O(3) is bonded in a distorted linear geometry to one Sr(1), one Sr(3), one Sr(6), one Sr(7), one Mn(2), and one Mn(3) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Sr(2), one Sr(5), one Sr(8), one Mn(1), and one Mn(4) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Sr(3), one Sr(4), one Sr(5), one Sr(6), one Mn(2), and one Mn(5) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Sr(3), one Sr(4), one Sr(5), one Sr(6), one Mn(1), and one Mn(5) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Sr(2), one Sr(8), one Mn(4), and one Mn(6) atom. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(7), one Sr(8), one Mg(1), one Mn(3), and one Mn(6) atom. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Sr(3), one Sr(4), one Sr(5), one Sr(6), one Mn(1), and one Mn(5) atom. In the tenth O site, O(10) is bonded in a 6-coordinate geometry to one Sr(3), one Sr(4), one Sr(5), one Sr(6), one Mn(2), and one Mn(5) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(7), one Sr(8), one Mg(1), one Mn(3), and one Mn(6) atom. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to one Sr(2), one Sr(7), one Sr(8), one Mg(1), and one Mn(6) atom. In the thirteenth O site, O(13) is bonded in a 5-coordinate geometry to one Sr(2), one Sr(5), two equivalent Sr(4), and one Mn(1) atom. In the fourteenth O site, O(14) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(6), two equivalent Sr(3), and one Mn(2) atom. In the fifteenth O site, O(15) is bonded to one Sr(1), one Sr(6), two equivalent Sr(7), one Mn(3), and one Mn(6) atom to form a mixture of distorted corner and edge-sharing OSr4Mn2 octahedra. The corner-sharing octahedral tilt angles are 10°. In the sixteenth O site, O(16) is bonded in a 6-coordinate geometry to one Sr(2), two equivalent Sr(8), one Mg(1), one Mn(4), and one Mn(6) atom. In the seventeenth O site, O(17) is bonded to one Sr(4), two equivalent Sr(5), one Mn(1), and one Mn(5) atom to form distorted OSr3Mn2 square pyramids that share  a cornercorner with one O(20)Sr4Mn2 octahedra and corners with two equivalent O(17)Sr3Mn2 square pyramids. The corner-sharing octahedral tilt angles are 2°. In the eighteenth O site, O(18) is bonded in a 5-coordinate geometry to one Sr(7), two equivalent Sr(1), one Mg(1), and one Mn(3) atom. In the nineteenth O site, O(19) is bonded in a 5-coordinate geometry to one Sr(4), one Sr(8), two equivalent Sr(2), and one Mn(4) atom. In the twentieth O site, O(20) is bonded to one Sr(3), one Sr(7), two equivalent Sr(6), one Mn(2), and one Mn(5) atom to form distorted OSr4Mn2 octahedra that share corners with two equivalent O(20)Sr4Mn2 octahedra,  a cornercorner with one O(17)Sr3Mn2 square pyramid, and edges with two equivalent O(15)Sr4Mn2 octahedra. The corner-sharing octahedral tilt angles are 6°.