Ba6MgCo2(Sb2O9)2 crystallizes in the triclinic P1 space group. There are six inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one O(12), one O(14), one O(15), one O(16), one O(8), one O(9), two equivalent O(4), two equivalent O(6), and two equivalent O(7) atoms to form distorted BaO12 cuboctahedra that share corners with six equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Sb(3)O6 octahedra, faces with three equivalent Ba(3)O12 cuboctahedra,  a faceface with one Sb(4)O6 octahedra, faces with three equivalent Co(2)O6 octahedra, and faces with three equivalent Sb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 13-21°. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to one O(11), one O(5), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. In the third Ba site, Ba(3) is bonded to one O(13), one O(17), one O(18), one O(4), one O(6), one O(7), two equivalent O(12), two equivalent O(8), and two equivalent O(9) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(3)O12 cuboctahedra, corners with three equivalent Sb(1)O6 octahedra, faces with three equivalent Ba(1)O12 cuboctahedra,  a faceface with one Sb(2)O6 octahedra, faces with three equivalent Co(2)O6 octahedra, and faces with three equivalent Sb(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-10°. In the fourth Ba site, Ba(4) is bonded in a 11-coordinate geometry to one O(1), one O(14), one O(15), one O(16), one O(2), two equivalent O(10), two equivalent O(11), and two equivalent O(5) atoms. In the fifth Ba site, Ba(5) is bonded in a 10-coordinate geometry to one O(10), one O(4), one O(6), one O(7), two equivalent O(14), two equivalent O(15), and two equivalent O(16) atoms. In the sixth Ba site, Ba(6) is bonded in a 10-coordinate geometry to one Co(1), one O(12), one O(8), one O(9), two equivalent O(13), two equivalent O(17), and two equivalent O(18) atoms. Mg(1) is bonded in a distorted trigonal non-coplanar geometry to one O(10), one O(11), and one O(5) atom. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a distorted trigonal planar geometry to one Ba(6), one O(1), one O(2), and one O(3) atom. In the second Co site, Co(2) is bonded to one O(12), one O(4), one O(6), one O(7), one O(8), and one O(9) atom to form CoO6 octahedra that share corners with three equivalent Sb(2)O6 octahedra, corners with three equivalent Sb(4)O6 octahedra, faces with three equivalent Ba(1)O12 cuboctahedra, and faces with three equivalent Ba(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-5°. There are four inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(1), one O(13), one O(17), one O(18), one O(2), and one O(3) atom to form SbO6 octahedra that share corners with three equivalent Ba(3)O12 cuboctahedra and  a faceface with one Sb(4)O6 octahedra. In the second Sb site, Sb(2) is bonded to one O(14), one O(15), one O(16), one O(4), one O(6), and one O(7) atom to form distorted SbO6 octahedra that share corners with three equivalent Co(2)O6 octahedra,  a faceface with one Ba(3)O12 cuboctahedra, faces with three equivalent Ba(1)O12 cuboctahedra, and  a faceface with one Sb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-5°. In the third Sb site, Sb(3) is bonded to one O(10), one O(11), one O(14), one O(15), one O(16), and one O(5) atom to form SbO6 octahedra that share corners with three equivalent Ba(1)O12 cuboctahedra and  a faceface with one Sb(2)O6 octahedra. In the fourth Sb site, Sb(4) is bonded to one O(12), one O(13), one O(17), one O(18), one O(8), and one O(9) atom to form SbO6 octahedra that share corners with three equivalent Co(2)O6 octahedra,  a faceface with one Ba(1)O12 cuboctahedra, faces with three equivalent Ba(3)O12 cuboctahedra, and  a faceface with one Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 2-5°. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Ba(4), two equivalent Ba(2), one Co(1), and one Sb(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Ba(4), two equivalent Ba(2), one Co(1), and one Sb(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Ba(2), one Co(1), and one Sb(1) atom. In the fourth O site, O(4) is bonded to one Ba(3), one Ba(5), two equivalent Ba(1), one Co(2), and one Sb(2) atom to form a mixture of distorted face, corner, and edge-sharing OBa4CoSb octahedra. The corner-sharing octahedral tilt angles range from 0-61°. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Ba(2), two equivalent Ba(4), one Mg(1), and one Sb(3) atom. In the sixth O site, O(6) is bonded to one Ba(3), one Ba(5), two equivalent Ba(1), one Co(2), and one Sb(2) atom to form a mixture of distorted face, corner, and edge-sharing OBa4CoSb octahedra. The corner-sharing octahedral tilt angles range from 2-60°. In the seventh O site, O(7) is bonded to one Ba(3), one Ba(5), two equivalent Ba(1), one Co(2), and one Sb(2) atom to form a mixture of distorted face, corner, and edge-sharing OBa4CoSb octahedra. The corner-sharing octahedral tilt angles range from 2-60°. In the eighth O site, O(8) is bonded to one Ba(1), one Ba(6), two equivalent Ba(3), one Co(2), and one Sb(4) atom to form a mixture of distorted face, corner, and edge-sharing OBa4CoSb octahedra. The corner-sharing octahedral tilt angles range from 2-61°. In the ninth O site, O(9) is bonded to one Ba(1), one Ba(6), two equivalent Ba(3), one Co(2), and one Sb(4) atom to form a mixture of distorted face, corner, and edge-sharing OBa4CoSb octahedra. The corner-sharing octahedral tilt angles range from 2-60°. In the tenth O site, O(10) is bonded in a distorted linear geometry to one Ba(5), two equivalent Ba(4), one Mg(1), and one Sb(3) atom. In the eleventh O site, O(11) is bonded in a 2-coordinate geometry to one Ba(2), two equivalent Ba(4), one Mg(1), and one Sb(3) atom. In the twelfth O site, O(12) is bonded to one Ba(1), one Ba(6), two equivalent Ba(3), one Co(2), and one Sb(4) atom to form a mixture of distorted face, corner, and edge-sharing OBa4CoSb octahedra. The corner-sharing octahedral tilt angles range from 2-61°. In the thirteenth O site, O(13) is bonded in a distorted L-shaped geometry to one Ba(3), two equivalent Ba(6), one Sb(1), and one Sb(4) atom. In the fourteenth O site, O(14) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(4), two equivalent Ba(5), one Sb(2), and one Sb(3) atom. In the fifteenth O site, O(15) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(4), two equivalent Ba(5), one Sb(2), and one Sb(3) atom. In the sixteenth O site, O(16) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(4), two equivalent Ba(5), one Sb(2), and one Sb(3) atom. In the seventeenth O site, O(17) is bonded in a distorted L-shaped geometry to one Ba(3), two equivalent Ba(6), one Sb(1), and one Sb(4) atom. In the eighteenth O site, O(18) is bonded in a distorted L-shaped geometry to one Ba(3), two equivalent Ba(6), one Sb(1), and one Sb(4) atom.
Ba6MgCo2(Sb2O9)2 crystallizes in the triclinic P1 space group. There are six inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one O(12), one O(14), one O(15), one O(16), one O(8), one O(9), two equivalent O(4), two equivalent O(6), and two equivalent O(7) atoms to form distorted BaO12 cuboctahedra that share corners with six equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Sb(3)O6 octahedra, faces with three equivalent Ba(3)O12 cuboctahedra,  a faceface with one Sb(4)O6 octahedra, faces with three equivalent Co(2)O6 octahedra, and faces with three equivalent Sb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 13-21°. The Ba(1)-O(12) bond length is 2.99 Å. The Ba(1)-O(14) bond length is 3.25 Å. The Ba(1)-O(15) bond length is 3.49 Å. The Ba(1)-O(16) bond length is 3.24 Å. The Ba(1)-O(8) bond length is 2.99 Å. The Ba(1)-O(9) bond length is 2.93 Å. There is one shorter (3.00 Å) and one longer (3.01 Å) Ba(1)-O(4) bond length. There is one shorter (3.00 Å) and one longer (3.01 Å) Ba(1)-O(6) bond length. There is one shorter (2.99 Å) and one longer (3.03 Å) Ba(1)-O(7) bond length. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to one O(11), one O(5), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. The Ba(2)-O(11) bond length is 2.85 Å. The Ba(2)-O(5) bond length is 2.85 Å. There is one shorter (3.00 Å) and one longer (3.04 Å) Ba(2)-O(1) bond length. There is one shorter (3.00 Å) and one longer (3.05 Å) Ba(2)-O(2) bond length. Both Ba(2)-O(3) bond lengths are 3.03 Å. In the third Ba site, Ba(3) is bonded to one O(13), one O(17), one O(18), one O(4), one O(6), one O(7), two equivalent O(12), two equivalent O(8), and two equivalent O(9) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(3)O12 cuboctahedra, corners with three equivalent Sb(1)O6 octahedra, faces with three equivalent Ba(1)O12 cuboctahedra,  a faceface with one Sb(2)O6 octahedra, faces with three equivalent Co(2)O6 octahedra, and faces with three equivalent Sb(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-10°. The Ba(3)-O(13) bond length is 3.16 Å. The Ba(3)-O(17) bond length is 3.16 Å. The Ba(3)-O(18) bond length is 3.24 Å. The Ba(3)-O(4) bond length is 2.96 Å. The Ba(3)-O(6) bond length is 3.04 Å. The Ba(3)-O(7) bond length is 3.04 Å. There is one shorter (2.99 Å) and one longer (3.03 Å) Ba(3)-O(12) bond length. There is one shorter (2.99 Å) and one longer (3.02 Å) Ba(3)-O(8) bond length. There is one shorter (3.00 Å) and one longer (3.01 Å) Ba(3)-O(9) bond length. In the fourth Ba site, Ba(4) is bonded in a 11-coordinate geometry to one O(1), one O(14), one O(15), one O(16), one O(2), two equivalent O(10), two equivalent O(11), and two equivalent O(5) atoms. The Ba(4)-O(1) bond length is 3.37 Å. The Ba(4)-O(14) bond length is 2.97 Å. The Ba(4)-O(15) bond length is 2.73 Å. The Ba(4)-O(16) bond length is 2.97 Å. The Ba(4)-O(2) bond length is 3.37 Å. Both Ba(4)-O(10) bond lengths are 3.01 Å. There is one shorter (2.91 Å) and one longer (3.15 Å) Ba(4)-O(11) bond length. There is one shorter (2.92 Å) and one longer (3.15 Å) Ba(4)-O(5) bond length. In the fifth Ba site, Ba(5) is bonded in a 10-coordinate geometry to one O(10), one O(4), one O(6), one O(7), two equivalent O(14), two equivalent O(15), and two equivalent O(16) atoms. The Ba(5)-O(10) bond length is 3.09 Å. The Ba(5)-O(4) bond length is 2.90 Å. The Ba(5)-O(6) bond length is 2.81 Å. The Ba(5)-O(7) bond length is 2.81 Å. There is one shorter (3.00 Å) and one longer (3.06 Å) Ba(5)-O(14) bond length. There is one shorter (3.06 Å) and one longer (3.08 Å) Ba(5)-O(15) bond length. There is one shorter (3.01 Å) and one longer (3.06 Å) Ba(5)-O(16) bond length. In the sixth Ba site, Ba(6) is bonded in a 10-coordinate geometry to one Co(1), one O(12), one O(8), one O(9), two equivalent O(13), two equivalent O(17), and two equivalent O(18) atoms. The Ba(6)-Co(1) bond length is 2.82 Å. The Ba(6)-O(12) bond length is 2.73 Å. The Ba(6)-O(8) bond length is 2.73 Å. The Ba(6)-O(9) bond length is 2.77 Å. There is one shorter (3.02 Å) and one longer (3.07 Å) Ba(6)-O(13) bond length. There is one shorter (3.01 Å) and one longer (3.07 Å) Ba(6)-O(17) bond length. Both Ba(6)-O(18) bond lengths are 3.05 Å. Mg(1) is bonded in a distorted trigonal non-coplanar geometry to one O(10), one O(11), and one O(5) atom. The Mg(1)-O(10) bond length is 1.93 Å. The Mg(1)-O(11) bond length is 1.94 Å. The Mg(1)-O(5) bond length is 1.94 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a distorted trigonal planar geometry to one Ba(6), one O(1), one O(2), and one O(3) atom. The Co(1)-O(1) bond length is 1.88 Å. The Co(1)-O(2) bond length is 1.88 Å. The Co(1)-O(3) bond length is 1.88 Å. In the second Co site, Co(2) is bonded to one O(12), one O(4), one O(6), one O(7), one O(8), and one O(9) atom to form CoO6 octahedra that share corners with three equivalent Sb(2)O6 octahedra, corners with three equivalent Sb(4)O6 octahedra, faces with three equivalent Ba(1)O12 cuboctahedra, and faces with three equivalent Ba(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-5°. The Co(2)-O(12) bond length is 2.22 Å. The Co(2)-O(4) bond length is 2.08 Å. The Co(2)-O(6) bond length is 2.09 Å. The Co(2)-O(7) bond length is 2.08 Å. The Co(2)-O(8) bond length is 2.21 Å. The Co(2)-O(9) bond length is 2.23 Å. There are four inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(1), one O(13), one O(17), one O(18), one O(2), and one O(3) atom to form SbO6 octahedra that share corners with three equivalent Ba(3)O12 cuboctahedra and  a faceface with one Sb(4)O6 octahedra. The Sb(1)-O(1) bond length is 2.00 Å. The Sb(1)-O(13) bond length is 2.11 Å. The Sb(1)-O(17) bond length is 2.11 Å. The Sb(1)-O(18) bond length is 2.11 Å. The Sb(1)-O(2) bond length is 1.99 Å. The Sb(1)-O(3) bond length is 1.99 Å. In the second Sb site, Sb(2) is bonded to one O(14), one O(15), one O(16), one O(4), one O(6), and one O(7) atom to form distorted SbO6 octahedra that share corners with three equivalent Co(2)O6 octahedra,  a faceface with one Ba(3)O12 cuboctahedra, faces with three equivalent Ba(1)O12 cuboctahedra, and  a faceface with one Sb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-5°. The Sb(2)-O(14) bond length is 2.26 Å. The Sb(2)-O(15) bond length is 2.35 Å. The Sb(2)-O(16) bond length is 2.27 Å. The Sb(2)-O(4) bond length is 2.03 Å. The Sb(2)-O(6) bond length is 2.04 Å. The Sb(2)-O(7) bond length is 2.05 Å. In the third Sb site, Sb(3) is bonded to one O(10), one O(11), one O(14), one O(15), one O(16), and one O(5) atom to form SbO6 octahedra that share corners with three equivalent Ba(1)O12 cuboctahedra and  a faceface with one Sb(2)O6 octahedra. The Sb(3)-O(10) bond length is 2.00 Å. The Sb(3)-O(11) bond length is 2.00 Å. The Sb(3)-O(14) bond length is 2.05 Å. The Sb(3)-O(15) bond length is 2.04 Å. The Sb(3)-O(16) bond length is 2.05 Å. The Sb(3)-O(5) bond length is 1.99 Å. In the fourth Sb site, Sb(4) is bonded to one O(12), one O(13), one O(17), one O(18), one O(8), and one O(9) atom to form SbO6 octahedra that share corners with three equivalent Co(2)O6 octahedra,  a faceface with one Ba(1)O12 cuboctahedra, faces with three equivalent Ba(3)O12 cuboctahedra, and  a faceface with one Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 2-5°. The Sb(4)-O(12) bond length is 1.98 Å. The Sb(4)-O(13) bond length is 2.09 Å. The Sb(4)-O(17) bond length is 2.09 Å. The Sb(4)-O(18) bond length is 2.10 Å. The Sb(4)-O(8) bond length is 1.98 Å. The Sb(4)-O(9) bond length is 1.98 Å. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Ba(4), two equivalent Ba(2), one Co(1), and one Sb(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Ba(4), two equivalent Ba(2), one Co(1), and one Sb(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Ba(2), one Co(1), and one Sb(1) atom. In the fourth O site, O(4) is bonded to one Ba(3), one Ba(5), two equivalent Ba(1), one Co(2), and one Sb(2) atom to form a mixture of distorted face, corner, and edge-sharing OBa4CoSb octahedra. The corner-sharing octahedral tilt angles range from 0-61°. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Ba(2), two equivalent Ba(4), one Mg(1), and one Sb(3) atom. In the sixth O site, O(6) is bonded to one Ba(3), one Ba(5), two equivalent Ba(1), one Co(2), and one Sb(2) atom to form a mixture of distorted face, corner, and edge-sharing OBa4CoSb octahedra. The corner-sharing octahedral tilt angles range from 2-60°. In the seventh O site, O(7) is bonded to one Ba(3), one Ba(5), two equivalent Ba(1), one Co(2), and one Sb(2) atom to form a mixture of distorted face, corner, and edge-sharing OBa4CoSb octahedra. The corner-sharing octahedral tilt angles range from 2-60°. In the eighth O site, O(8) is bonded to one Ba(1), one Ba(6), two equivalent Ba(3), one Co(2), and one Sb(4) atom to form a mixture of distorted face, corner, and edge-sharing OBa4CoSb octahedra. The corner-sharing octahedral tilt angles range from 2-61°. In the ninth O site, O(9) is bonded to one Ba(1), one Ba(6), two equivalent Ba(3), one Co(2), and one Sb(4) atom to form a mixture of distorted face, corner, and edge-sharing OBa4CoSb octahedra. The corner-sharing octahedral tilt angles range from 2-60°. In the tenth O site, O(10) is bonded in a distorted linear geometry to one Ba(5), two equivalent Ba(4), one Mg(1), and one Sb(3) atom. In the eleventh O site, O(11) is bonded in a 2-coordinate geometry to one Ba(2), two equivalent Ba(4), one Mg(1), and one Sb(3) atom. In the twelfth O site, O(12) is bonded to one Ba(1), one Ba(6), two equivalent Ba(3), one Co(2), and one Sb(4) atom to form a mixture of distorted face, corner, and edge-sharing OBa4CoSb octahedra. The corner-sharing octahedral tilt angles range from 2-61°. In the thirteenth O site, O(13) is bonded in a distorted L-shaped geometry to one Ba(3), two equivalent Ba(6), one Sb(1), and one Sb(4) atom. In the fourteenth O site, O(14) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(4), two equivalent Ba(5), one Sb(2), and one Sb(3) atom. In the fifteenth O site, O(15) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(4), two equivalent Ba(5), one Sb(2), and one Sb(3) atom. In the sixteenth O site, O(16) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(4), two equivalent Ba(5), one Sb(2), and one Sb(3) atom. In the seventeenth O site, O(17) is bonded in a distorted L-shaped geometry to one Ba(3), two equivalent Ba(6), one Sb(1), and one Sb(4) atom. In the eighteenth O site, O(18) is bonded in a distorted L-shaped geometry to one Ba(3), two equivalent Ba(6), one Sb(1), and one Sb(4) atom.