Ca8Ti2Mn6O23 crystallizes in the orthorhombic Pmm2 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a distorted q6 geometry to one O(10), one O(11), one O(12), one O(13), one O(14), one O(15), one O(2), one O(4), one O(6), one O(8), and one O(9) atom. In the second Ca site, Ca(2) is bonded in a 12-coordinate geometry to one O(1), one O(10), one O(11), one O(12), one O(13), one O(14), one O(15), one O(3), one O(5), one O(7), one O(8), and one O(9) atom. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), two equivalent O(12), and two equivalent O(8) atoms to form TiO5 trigonal bipyramids that share corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, and  a cornercorner with one Mn(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 13-19°. In the second Ti site, Ti(2) is bonded to one O(4), one O(5), two equivalent O(14), and two equivalent O(8) atoms to form TiO6 octahedra that share corners with two equivalent Mn(4)O6 octahedra, corners with two equivalent Mn(5)O6 octahedra, and corners with two equivalent Ti(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 0-3°. There are six inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), two equivalent O(13), and two equivalent O(9) atoms to form MnO5 square pyramids that share corners with two equivalent Mn(3)O6 octahedra, corners with two equivalent Mn(4)O6 octahedra, and  a cornercorner with one Ti(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 10-11°. In the second Mn site, Mn(2) is bonded to one O(2), one O(3), two equivalent O(10), and two equivalent O(12) atoms to form MnO6 octahedra that share corners with two equivalent Mn(3)O6 octahedra, corners with two equivalent Mn(5)O6 octahedra, and corners with two equivalent Ti(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 0-3°. In the third Mn site, Mn(3) is bonded to one O(2), one O(3), two equivalent O(11), and two equivalent O(13) atoms to form MnO6 octahedra that share corners with two equivalent Mn(2)O6 octahedra, corners with two equivalent Mn(6)O6 octahedra, and corners with two equivalent Mn(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 0-4°. In the fourth Mn site, Mn(4) is bonded to one O(4), one O(5), two equivalent O(15), and two equivalent O(9) atoms to form MnO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Mn(6)O6 octahedra, and corners with two equivalent Mn(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 0-4°. In the fifth Mn site, Mn(5) is bonded to one O(6), one O(7), two equivalent O(10), and two equivalent O(14) atoms to form MnO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, and corners with two equivalent Mn(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the sixth Mn site, Mn(6) is bonded to one O(6), one O(7), two equivalent O(11), and two equivalent O(15) atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to four equivalent Ca(2), one Ti(1), and one Mn(1) atom. In the second O site, O(2) is bonded in a distorted linear geometry to four equivalent Ca(1), one Mn(2), and one Mn(3) atom. In the third O site, O(3) is bonded to four equivalent Ca(2), one Mn(2), and one Mn(3) atom to form a mixture of distorted edge, corner, and face-sharing OCa4Mn2 octahedra. The corner-sharing octahedral tilt angles are 54°. In the fourth O site, O(4) is bonded in a distorted linear geometry to four equivalent Ca(1), one Ti(2), and one Mn(4) atom. In the fifth O site, O(5) is bonded in a distorted linear geometry to four equivalent Ca(2), one Ti(2), and one Mn(4) atom. In the sixth O site, O(6) is bonded to four equivalent Ca(1), one Mn(5), and one Mn(6) atom to form a mixture of distorted corner and face-sharing OCa4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the seventh O site, O(7) is bonded to four equivalent Ca(2), one Mn(5), and one Mn(6) atom to form a mixture of distorted edge, corner, and face-sharing OCa4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Ti(1), and one Ti(2) atom. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Mn(1), and one Mn(4) atom. In the tenth O site, O(10) is bonded to two equivalent Ca(1), two equivalent Ca(2), one Mn(2), and one Mn(5) atom to form a mixture of distorted edge, corner, and face-sharing OCa4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 2-56°. In the eleventh O site, O(11) is bonded to two equivalent Ca(1), two equivalent Ca(2), one Mn(3), and one Mn(6) atom to form a mixture of distorted edge, corner, and face-sharing OCa4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 4-5°. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Ti(1), and one Mn(2) atom. In the thirteenth O site, O(13) is bonded in a 2-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Mn(1), and one Mn(3) atom. In the fourteenth O site, O(14) is bonded in a distorted linear geometry to two equivalent Ca(1), two equivalent Ca(2), one Ti(2), and one Mn(5) atom. In the fifteenth O site, O(15) is bonded to two equivalent Ca(1), two equivalent Ca(2), one Mn(4), and one Mn(6) atom to form a mixture of distorted corner and face-sharing OCa4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 4-56°.
Ca8Ti2Mn6O23 crystallizes in the orthorhombic Pmm2 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a distorted q6 geometry to one O(10), one O(11), one O(12), one O(13), one O(14), one O(15), one O(2), one O(4), one O(6), one O(8), and one O(9) atom. The Ca(1)-O(10) bond length is 2.68 Å. The Ca(1)-O(11) bond length is 2.67 Å. The Ca(1)-O(12) bond length is 2.63 Å. The Ca(1)-O(13) bond length is 2.62 Å. The Ca(1)-O(14) bond length is 2.70 Å. The Ca(1)-O(15) bond length is 2.70 Å. The Ca(1)-O(2) bond length is 2.68 Å. The Ca(1)-O(4) bond length is 2.74 Å. The Ca(1)-O(6) bond length is 2.61 Å. The Ca(1)-O(8) bond length is 2.59 Å. The Ca(1)-O(9) bond length is 2.65 Å. In the second Ca site, Ca(2) is bonded in a 12-coordinate geometry to one O(1), one O(10), one O(11), one O(12), one O(13), one O(14), one O(15), one O(3), one O(5), one O(7), one O(8), and one O(9) atom. The Ca(2)-O(1) bond length is 2.87 Å. The Ca(2)-O(10) bond length is 2.65 Å. The Ca(2)-O(11) bond length is 2.53 Å. The Ca(2)-O(12) bond length is 2.97 Å. The Ca(2)-O(13) bond length is 2.86 Å. The Ca(2)-O(14) bond length is 2.70 Å. The Ca(2)-O(15) bond length is 2.58 Å. The Ca(2)-O(3) bond length is 2.68 Å. The Ca(2)-O(5) bond length is 2.76 Å. The Ca(2)-O(7) bond length is 2.56 Å. The Ca(2)-O(8) bond length is 3.08 Å. The Ca(2)-O(9) bond length is 2.89 Å. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), two equivalent O(12), and two equivalent O(8) atoms to form TiO5 trigonal bipyramids that share corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, and  a cornercorner with one Mn(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 13-19°. The Ti(1)-O(1) bond length is 1.76 Å. Both Ti(1)-O(12) bond lengths are 1.93 Å. Both Ti(1)-O(8) bond lengths are 1.91 Å. In the second Ti site, Ti(2) is bonded to one O(4), one O(5), two equivalent O(14), and two equivalent O(8) atoms to form TiO6 octahedra that share corners with two equivalent Mn(4)O6 octahedra, corners with two equivalent Mn(5)O6 octahedra, and corners with two equivalent Ti(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 0-3°. The Ti(2)-O(4) bond length is 1.90 Å. The Ti(2)-O(5) bond length is 1.98 Å. Both Ti(2)-O(14) bond lengths are 1.93 Å. Both Ti(2)-O(8) bond lengths are 1.98 Å. There are six inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), two equivalent O(13), and two equivalent O(9) atoms to form MnO5 square pyramids that share corners with two equivalent Mn(3)O6 octahedra, corners with two equivalent Mn(4)O6 octahedra, and  a cornercorner with one Ti(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 10-11°. The Mn(1)-O(1) bond length is 1.97 Å. Both Mn(1)-O(13) bond lengths are 1.91 Å. Both Mn(1)-O(9) bond lengths are 1.91 Å. In the second Mn site, Mn(2) is bonded to one O(2), one O(3), two equivalent O(10), and two equivalent O(12) atoms to form MnO6 octahedra that share corners with two equivalent Mn(3)O6 octahedra, corners with two equivalent Mn(5)O6 octahedra, and corners with two equivalent Ti(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 0-3°. The Mn(2)-O(2) bond length is 1.89 Å. The Mn(2)-O(3) bond length is 1.96 Å. Both Mn(2)-O(10) bond lengths are 1.92 Å. Both Mn(2)-O(12) bond lengths are 1.93 Å. In the third Mn site, Mn(3) is bonded to one O(2), one O(3), two equivalent O(11), and two equivalent O(13) atoms to form MnO6 octahedra that share corners with two equivalent Mn(2)O6 octahedra, corners with two equivalent Mn(6)O6 octahedra, and corners with two equivalent Mn(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 0-4°. The Mn(3)-O(2) bond length is 1.88 Å. The Mn(3)-O(3) bond length is 1.95 Å. Both Mn(3)-O(11) bond lengths are 1.92 Å. Both Mn(3)-O(13) bond lengths are 1.94 Å. In the fourth Mn site, Mn(4) is bonded to one O(4), one O(5), two equivalent O(15), and two equivalent O(9) atoms to form MnO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Mn(6)O6 octahedra, and corners with two equivalent Mn(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 0-4°. The Mn(4)-O(4) bond length is 1.86 Å. The Mn(4)-O(5) bond length is 1.94 Å. Both Mn(4)-O(15) bond lengths are 1.92 Å. Both Mn(4)-O(9) bond lengths are 1.94 Å. In the fifth Mn site, Mn(5) is bonded to one O(6), one O(7), two equivalent O(10), and two equivalent O(14) atoms to form MnO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, and corners with two equivalent Mn(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. The Mn(5)-O(6) bond length is 1.92 Å. The Mn(5)-O(7) bond length is 1.92 Å. Both Mn(5)-O(10) bond lengths are 1.92 Å. Both Mn(5)-O(14) bond lengths are 1.90 Å. In the sixth Mn site, Mn(6) is bonded to one O(6), one O(7), two equivalent O(11), and two equivalent O(15) atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. The Mn(6)-O(6) bond length is 1.91 Å. The Mn(6)-O(7) bond length is 1.93 Å. Both Mn(6)-O(11) bond lengths are 1.92 Å. Both Mn(6)-O(15) bond lengths are 1.92 Å. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to four equivalent Ca(2), one Ti(1), and one Mn(1) atom. In the second O site, O(2) is bonded in a distorted linear geometry to four equivalent Ca(1), one Mn(2), and one Mn(3) atom. In the third O site, O(3) is bonded to four equivalent Ca(2), one Mn(2), and one Mn(3) atom to form a mixture of distorted edge, corner, and face-sharing OCa4Mn2 octahedra. The corner-sharing octahedral tilt angles are 54°. In the fourth O site, O(4) is bonded in a distorted linear geometry to four equivalent Ca(1), one Ti(2), and one Mn(4) atom. In the fifth O site, O(5) is bonded in a distorted linear geometry to four equivalent Ca(2), one Ti(2), and one Mn(4) atom. In the sixth O site, O(6) is bonded to four equivalent Ca(1), one Mn(5), and one Mn(6) atom to form a mixture of distorted corner and face-sharing OCa4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the seventh O site, O(7) is bonded to four equivalent Ca(2), one Mn(5), and one Mn(6) atom to form a mixture of distorted edge, corner, and face-sharing OCa4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Ti(1), and one Ti(2) atom. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Mn(1), and one Mn(4) atom. In the tenth O site, O(10) is bonded to two equivalent Ca(1), two equivalent Ca(2), one Mn(2), and one Mn(5) atom to form a mixture of distorted edge, corner, and face-sharing OCa4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 2-56°. In the eleventh O site, O(11) is bonded to two equivalent Ca(1), two equivalent Ca(2), one Mn(3), and one Mn(6) atom to form a mixture of distorted edge, corner, and face-sharing OCa4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 4-5°. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Ti(1), and one Mn(2) atom. In the thirteenth O site, O(13) is bonded in a 2-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Mn(1), and one Mn(3) atom. In the fourteenth O site, O(14) is bonded in a distorted linear geometry to two equivalent Ca(1), two equivalent Ca(2), one Ti(2), and one Mn(5) atom. In the fifteenth O site, O(15) is bonded to two equivalent Ca(1), two equivalent Ca(2), one Mn(4), and one Mn(6) atom to form a mixture of distorted corner and face-sharing OCa4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 4-56°.