Ba2Mg2Cr3Tl2O10 crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one O(9), two equivalent O(6), and four equivalent O(7) atoms. In the second Ba site, Ba(2) is bonded to one O(4) and four equivalent O(2) atoms to form distorted BaO5 trigonal bipyramids that share corners with four equivalent Ba(2)O5 trigonal bipyramids, corners with four equivalent Cr(1)O5 trigonal bipyramids, and edges with four equivalent Ba(2)O5 trigonal bipyramids. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(10), two equivalent O(1), and two equivalent O(3) atoms to form distorted MgO5 trigonal bipyramids that share corners with four equivalent Mg(1)O5 trigonal bipyramids and edges with four equivalent Cr(1)O5 trigonal bipyramids. In the second Mg site, Mg(2) is bonded in a 7-coordinate geometry to one O(10), two equivalent O(5), two equivalent O(6), and two equivalent O(8) atoms. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(2), two equivalent O(1), and two equivalent O(3) atoms to form distorted CrO5 trigonal bipyramids that share corners with four equivalent Ba(2)O5 trigonal bipyramids, corners with four equivalent Cr(1)O5 trigonal bipyramids, and edges with four equivalent Mg(1)O5 trigonal bipyramids. In the second Cr site, Cr(2) is bonded to one O(7), two equivalent O(6), and two equivalent O(8) atoms to form corner-sharing CrO5 trigonal bipyramids. In the third Cr site, Cr(3) is bonded in a distorted square co-planar geometry to two equivalent O(10) and two equivalent O(5) atoms. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 3-coordinate geometry to one O(4) and two equivalent O(9) atoms. In the second Tl site, Tl(2) is bonded in a 3-coordinate geometry to one O(9) and two equivalent O(4) atoms. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to two equivalent Mg(1) and two equivalent Cr(1) atoms. In the second O site, O(2) is bonded to four equivalent Ba(2) and one Cr(1) atom to form a mixture of distorted corner and edge-sharing OBa4Cr square pyramids. In the third O site, O(3) is bonded in a distorted see-saw-like geometry to two equivalent Mg(1) and two equivalent Cr(1) atoms. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Ba(2), one Tl(1), and two equivalent Tl(2) atoms. In the fifth O site, O(5) is bonded in a distorted see-saw-like geometry to two equivalent Mg(2) and two equivalent Cr(3) atoms. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Mg(2), and two equivalent Cr(2) atoms. In the seventh O site, O(7) is bonded to four equivalent Ba(1) and one Cr(2) atom to form distorted OBa4Cr square pyramids that share corners with four equivalent O(7)Ba4Cr square pyramids, corners with two equivalent O(8)Mg2Cr2 trigonal pyramids, and edges with four equivalent O(7)Ba4Cr square pyramids. In the eighth O site, O(8) is bonded to two equivalent Mg(2) and two equivalent Cr(2) atoms to form distorted OMg2Cr2 trigonal pyramids that share corners with two equivalent O(7)Ba4Cr square pyramids and corners with four equivalent O(8)Mg2Cr2 trigonal pyramids. In the ninth O site, O(9) is bonded in a rectangular see-saw-like geometry to one Ba(1), one Tl(2), and two equivalent Tl(1) atoms. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Mg(1), one Mg(2), and two equivalent Cr(3) atoms.
Ba2Mg2Cr3Tl2O10 crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one O(9), two equivalent O(6), and four equivalent O(7) atoms. The Ba(1)-O(9) bond length is 2.75 Å. There is one shorter (2.95 Å) and one longer (3.11 Å) Ba(1)-O(6) bond length. There are two shorter (2.72 Å) and two longer (2.75 Å) Ba(1)-O(7) bond lengths. In the second Ba site, Ba(2) is bonded to one O(4) and four equivalent O(2) atoms to form distorted BaO5 trigonal bipyramids that share corners with four equivalent Ba(2)O5 trigonal bipyramids, corners with four equivalent Cr(1)O5 trigonal bipyramids, and edges with four equivalent Ba(2)O5 trigonal bipyramids. The Ba(2)-O(4) bond length is 2.65 Å. There are a spread of Ba(2)-O(2) bond distances ranging from 2.73-2.78 Å. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(10), two equivalent O(1), and two equivalent O(3) atoms to form distorted MgO5 trigonal bipyramids that share corners with four equivalent Mg(1)O5 trigonal bipyramids and edges with four equivalent Cr(1)O5 trigonal bipyramids. The Mg(1)-O(10) bond length is 2.05 Å. There is one shorter (2.12 Å) and one longer (2.14 Å) Mg(1)-O(1) bond length. There is one shorter (2.05 Å) and one longer (2.06 Å) Mg(1)-O(3) bond length. In the second Mg site, Mg(2) is bonded in a 7-coordinate geometry to one O(10), two equivalent O(5), two equivalent O(6), and two equivalent O(8) atoms. The Mg(2)-O(10) bond length is 2.68 Å. There is one shorter (2.23 Å) and one longer (2.36 Å) Mg(2)-O(5) bond length. There is one shorter (2.22 Å) and one longer (2.54 Å) Mg(2)-O(6) bond length. There is one shorter (2.12 Å) and one longer (2.16 Å) Mg(2)-O(8) bond length. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(2), two equivalent O(1), and two equivalent O(3) atoms to form distorted CrO5 trigonal bipyramids that share corners with four equivalent Ba(2)O5 trigonal bipyramids, corners with four equivalent Cr(1)O5 trigonal bipyramids, and edges with four equivalent Mg(1)O5 trigonal bipyramids. The Cr(1)-O(2) bond length is 1.92 Å. Both Cr(1)-O(1) bond lengths are 1.95 Å. Both Cr(1)-O(3) bond lengths are 2.01 Å. In the second Cr site, Cr(2) is bonded to one O(7), two equivalent O(6), and two equivalent O(8) atoms to form corner-sharing CrO5 trigonal bipyramids. The Cr(2)-O(7) bond length is 1.90 Å. Both Cr(2)-O(6) bond lengths are 1.95 Å. There is one shorter (2.00 Å) and one longer (2.04 Å) Cr(2)-O(8) bond length. In the third Cr site, Cr(3) is bonded in a distorted square co-planar geometry to two equivalent O(10) and two equivalent O(5) atoms. There is one shorter (1.94 Å) and one longer (1.95 Å) Cr(3)-O(10) bond length. There is one shorter (1.98 Å) and one longer (2.03 Å) Cr(3)-O(5) bond length. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 3-coordinate geometry to one O(4) and two equivalent O(9) atoms. The Tl(1)-O(4) bond length is 2.49 Å. There is one shorter (2.53 Å) and one longer (2.56 Å) Tl(1)-O(9) bond length. In the second Tl site, Tl(2) is bonded in a 3-coordinate geometry to one O(9) and two equivalent O(4) atoms. The Tl(2)-O(9) bond length is 2.47 Å. There is one shorter (2.54 Å) and one longer (2.55 Å) Tl(2)-O(4) bond length. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to two equivalent Mg(1) and two equivalent Cr(1) atoms. In the second O site, O(2) is bonded to four equivalent Ba(2) and one Cr(1) atom to form a mixture of distorted corner and edge-sharing OBa4Cr square pyramids. In the third O site, O(3) is bonded in a distorted see-saw-like geometry to two equivalent Mg(1) and two equivalent Cr(1) atoms. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Ba(2), one Tl(1), and two equivalent Tl(2) atoms. In the fifth O site, O(5) is bonded in a distorted see-saw-like geometry to two equivalent Mg(2) and two equivalent Cr(3) atoms. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Mg(2), and two equivalent Cr(2) atoms. In the seventh O site, O(7) is bonded to four equivalent Ba(1) and one Cr(2) atom to form distorted OBa4Cr square pyramids that share corners with four equivalent O(7)Ba4Cr square pyramids, corners with two equivalent O(8)Mg2Cr2 trigonal pyramids, and edges with four equivalent O(7)Ba4Cr square pyramids. In the eighth O site, O(8) is bonded to two equivalent Mg(2) and two equivalent Cr(2) atoms to form distorted OMg2Cr2 trigonal pyramids that share corners with two equivalent O(7)Ba4Cr square pyramids and corners with four equivalent O(8)Mg2Cr2 trigonal pyramids. In the ninth O site, O(9) is bonded in a rectangular see-saw-like geometry to one Ba(1), one Tl(2), and two equivalent Tl(1) atoms. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Mg(1), one Mg(2), and two equivalent Cr(3) atoms.