Ca8Cr2Mn6O23 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 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 to form distorted CaO12 cuboctahedra that share corners with four equivalent Ca(2)O12 cuboctahedra, faces with four equivalent Ca(2)O12 cuboctahedra,  a faceface with one Cr(2)O6 octahedra,  a faceface with one Mn(2)O6 octahedra,  a faceface with one Mn(3)O6 octahedra,  a faceface with one Mn(4)O6 octahedra,  a faceface with one Mn(5)O6 octahedra,  a faceface with one Mn(6)O6 octahedra,  a faceface with one Cr(1)O5 square pyramid, and  a faceface with one Mn(1)O5 square pyramid. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), two equivalent O(12), and two equivalent O(8) atoms to form CrO5 square pyramids that share corners with two equivalent Cr(2)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra,  a cornercorner with one Mn(1)O5 square pyramid, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 15-19°. In the second Cr site, Cr(2) is bonded to one O(4), one O(5), two equivalent O(14), and two equivalent O(8) atoms to form CrO6 octahedra that share corners with two equivalent Mn(4)O6 octahedra, corners with two equivalent Mn(5)O6 octahedra, corners with two equivalent Cr(1)O5 square pyramids, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-4°. 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,  a cornercorner with one Cr(1)O5 square pyramid, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 12-13°. 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, corners with two equivalent Cr(1)O5 square pyramids, and faces with four equivalent Ca(2)O12 cuboctahedra. 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, corners with two equivalent Mn(1)O5 square pyramids, and faces with four equivalent Ca(2)O12 cuboctahedra. 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 Cr(2)O6 octahedra, corners with two equivalent Mn(6)O6 octahedra, corners with two equivalent Mn(1)O5 square pyramids, and faces with four equivalent Ca(2)O12 cuboctahedra. 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 Cr(2)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, corners with two equivalent Mn(6)O6 octahedra, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-4°. 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 MnO6 octahedra that share corners with two equivalent Mn(3)O6 octahedra, corners with two equivalent Mn(4)O6 octahedra, corners with two equivalent Mn(5)O6 octahedra, and faces with four equivalent Ca(2)O12 cuboctahedra. 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 Cr(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 distorted OCa4Mn2 octahedra that share corners with four equivalent O(15)Ca4Mn2 octahedra, corners with four equivalent O(5)Ca4MnCr octahedra, edges with two equivalent O(7)Ca4Mn2 octahedra, faces with two equivalent O(10)Ca4Mn2 octahedra, and faces with two equivalent O(11)Ca4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 6-55°. In the fourth O site, O(4) is bonded in a distorted linear geometry to four equivalent Ca(1), one Cr(2), and one Mn(4) atom. In the fifth O site, O(5) is bonded to four equivalent Ca(2), one Cr(2), and one Mn(4) atom to form a mixture of distorted edge, corner, and face-sharing OCa4MnCr octahedra. The corner-sharing octahedral tilt angles range from 6-60°. 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 distorted OCa4Mn2 octahedra that share corners with two equivalent O(6)Ca4Mn2 octahedra, edges with two equivalent O(3)Ca4Mn2 octahedra, edges with two equivalent O(5)Ca4MnCr octahedra, faces with two equivalent O(10)Ca4Mn2 octahedra, faces with two equivalent O(11)Ca4Mn2 octahedra, and faces with two equivalent O(15)Ca4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Cr(1), and one Cr(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 distorted OCa4Mn2 octahedra that share corners with two equivalent O(10)Ca4Mn2 octahedra, corners with two equivalent O(5)Ca4MnCr octahedra, corners with four equivalent O(15)Ca4Mn2 octahedra, edges with two equivalent O(11)Ca4Mn2 octahedra,  a faceface with one O(3)Ca4Mn2 octahedra,  a faceface with one O(6)Ca4Mn2 octahedra, and  a faceface with one O(7)Ca4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 2-60°. 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 distorted OCa4Mn2 octahedra that share corners with two equivalent O(11)Ca4Mn2 octahedra, corners with two equivalent O(5)Ca4MnCr octahedra, edges with two equivalent O(10)Ca4Mn2 octahedra,  a faceface with one O(3)Ca4Mn2 octahedra,  a faceface with one O(6)Ca4Mn2 octahedra,  a faceface with one O(7)Ca4Mn2 octahedra, and faces with two equivalent O(15)Ca4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 4-56°. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Cr(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 Cr(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 distorted OCa4Mn2 octahedra that share corners with two equivalent O(15)Ca4Mn2 octahedra, corners with two equivalent O(3)Ca4Mn2 octahedra, corners with four equivalent O(10)Ca4Mn2 octahedra,  a faceface with one O(6)Ca4Mn2 octahedra,  a faceface with one O(7)Ca4Mn2 octahedra,  a faceface with one O(5)Ca4MnCr octahedra, and faces with two equivalent O(11)Ca4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 4-56°.
Ca8Cr2Mn6O23 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 2.55 Å. The Ca(1)-O(13) bond length is 2.58 Å. The Ca(1)-O(14) bond length is 2.72 Å. The Ca(1)-O(15) bond length is 2.70 Å. The Ca(1)-O(2) bond length is 2.67 Å. The Ca(1)-O(4) bond length is 2.73 Å. The Ca(1)-O(6) bond length is 2.62 Å. The Ca(1)-O(8) bond length is 2.60 Å. The Ca(1)-O(9) bond length is 2.61 Å. In the second Ca site, Ca(2) is bonded 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 to form distorted CaO12 cuboctahedra that share corners with four equivalent Ca(2)O12 cuboctahedra, faces with four equivalent Ca(2)O12 cuboctahedra,  a faceface with one Cr(2)O6 octahedra,  a faceface with one Mn(2)O6 octahedra,  a faceface with one Mn(3)O6 octahedra,  a faceface with one Mn(4)O6 octahedra,  a faceface with one Mn(5)O6 octahedra,  a faceface with one Mn(6)O6 octahedra,  a faceface with one Cr(1)O5 square pyramid, and  a faceface with one Mn(1)O5 square pyramid. The Ca(2)-O(1) bond length is 2.83 Å. The Ca(2)-O(10) bond length is 2.64 Å. The Ca(2)-O(11) bond length is 2.54 Å. The Ca(2)-O(12) bond length is 3.03 Å. The Ca(2)-O(13) bond length is 2.87 Å. The Ca(2)-O(14) bond length is 2.66 Å. The Ca(2)-O(15) bond length is 2.57 Å. The Ca(2)-O(3) bond length is 2.69 Å. The Ca(2)-O(5) bond length is 2.71 Å. The Ca(2)-O(7) bond length is 2.56 Å. The Ca(2)-O(8) bond length is 2.99 Å. The Ca(2)-O(9) bond length is 2.86 Å. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), two equivalent O(12), and two equivalent O(8) atoms to form CrO5 square pyramids that share corners with two equivalent Cr(2)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra,  a cornercorner with one Mn(1)O5 square pyramid, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 15-19°. The Cr(1)-O(1) bond length is 1.79 Å. Both Cr(1)-O(12) bond lengths are 1.85 Å. Both Cr(1)-O(8) bond lengths are 1.87 Å. In the second Cr site, Cr(2) is bonded to one O(4), one O(5), two equivalent O(14), and two equivalent O(8) atoms to form CrO6 octahedra that share corners with two equivalent Mn(4)O6 octahedra, corners with two equivalent Mn(5)O6 octahedra, corners with two equivalent Cr(1)O5 square pyramids, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-4°. The Cr(2)-O(4) bond length is 1.86 Å. The Cr(2)-O(5) bond length is 1.95 Å. Both Cr(2)-O(14) bond lengths are 1.88 Å. Both Cr(2)-O(8) bond lengths are 1.99 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,  a cornercorner with one Cr(1)O5 square pyramid, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 12-13°. The Mn(1)-O(1) bond length is 1.95 Å. Both Mn(1)-O(13) bond lengths are 1.89 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, corners with two equivalent Cr(1)O5 square pyramids, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. The Mn(2)-O(2) bond length is 1.90 Å. The Mn(2)-O(3) bond length is 1.93 Å. Both Mn(2)-O(10) bond lengths are 1.91 Å. Both Mn(2)-O(12) bond lengths are 2.00 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, corners with two equivalent Mn(1)O5 square pyramids, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-4°. The Mn(3)-O(2) bond length is 1.87 Å. The Mn(3)-O(3) bond length is 1.95 Å. Both Mn(3)-O(11) bond lengths are 1.91 Å. Both Mn(3)-O(13) bond lengths are 1.93 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 Cr(2)O6 octahedra, corners with two equivalent Mn(6)O6 octahedra, corners with two equivalent Mn(1)O5 square pyramids, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-4°. The Mn(4)-O(4) bond length is 1.89 Å. The Mn(4)-O(5) bond length is 1.95 Å. Both Mn(4)-O(15) bond lengths are 1.89 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 Cr(2)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, corners with two equivalent Mn(6)O6 octahedra, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-4°. The Mn(5)-O(6) bond length is 1.91 Å. The Mn(5)-O(7) bond length is 1.91 Å. Both Mn(5)-O(10) bond lengths are 1.92 Å. Both Mn(5)-O(14) bond lengths are 1.91 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 MnO6 octahedra that share corners with two equivalent Mn(3)O6 octahedra, corners with two equivalent Mn(4)O6 octahedra, corners with two equivalent Mn(5)O6 octahedra, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-4°. The Mn(6)-O(6) bond length is 1.90 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 1.91 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 Cr(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 distorted OCa4Mn2 octahedra that share corners with four equivalent O(15)Ca4Mn2 octahedra, corners with four equivalent O(5)Ca4MnCr octahedra, edges with two equivalent O(7)Ca4Mn2 octahedra, faces with two equivalent O(10)Ca4Mn2 octahedra, and faces with two equivalent O(11)Ca4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 6-55°. In the fourth O site, O(4) is bonded in a distorted linear geometry to four equivalent Ca(1), one Cr(2), and one Mn(4) atom. In the fifth O site, O(5) is bonded to four equivalent Ca(2), one Cr(2), and one Mn(4) atom to form a mixture of distorted edge, corner, and face-sharing OCa4MnCr octahedra. The corner-sharing octahedral tilt angles range from 6-60°. 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 distorted OCa4Mn2 octahedra that share corners with two equivalent O(6)Ca4Mn2 octahedra, edges with two equivalent O(3)Ca4Mn2 octahedra, edges with two equivalent O(5)Ca4MnCr octahedra, faces with two equivalent O(10)Ca4Mn2 octahedra, faces with two equivalent O(11)Ca4Mn2 octahedra, and faces with two equivalent O(15)Ca4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Cr(1), and one Cr(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 distorted OCa4Mn2 octahedra that share corners with two equivalent O(10)Ca4Mn2 octahedra, corners with two equivalent O(5)Ca4MnCr octahedra, corners with four equivalent O(15)Ca4Mn2 octahedra, edges with two equivalent O(11)Ca4Mn2 octahedra,  a faceface with one O(3)Ca4Mn2 octahedra,  a faceface with one O(6)Ca4Mn2 octahedra, and  a faceface with one O(7)Ca4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 2-60°. 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 distorted OCa4Mn2 octahedra that share corners with two equivalent O(11)Ca4Mn2 octahedra, corners with two equivalent O(5)Ca4MnCr octahedra, edges with two equivalent O(10)Ca4Mn2 octahedra,  a faceface with one O(3)Ca4Mn2 octahedra,  a faceface with one O(6)Ca4Mn2 octahedra,  a faceface with one O(7)Ca4Mn2 octahedra, and faces with two equivalent O(15)Ca4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 4-56°. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Cr(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 Cr(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 distorted OCa4Mn2 octahedra that share corners with two equivalent O(15)Ca4Mn2 octahedra, corners with two equivalent O(3)Ca4Mn2 octahedra, corners with four equivalent O(10)Ca4Mn2 octahedra,  a faceface with one O(6)Ca4Mn2 octahedra,  a faceface with one O(7)Ca4Mn2 octahedra,  a faceface with one O(5)Ca4MnCr octahedra, and faces with two equivalent O(11)Ca4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 4-56°.