Ba2MgTi3Tl2O10 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), two equivalent O(7), and two equivalent O(8) atoms. In the second Ba site, Ba(2) is bonded in a 6-coordinate geometry to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms. Mg(1) is bonded in a distorted trigonal non-coplanar geometry to one O(7) and two equivalent O(9) atoms. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(10), one O(2), one O(3), and two equivalent O(1) atoms to form a mixture of distorted corner and edge-sharing TiO5 trigonal bipyramids. In the second Ti site, Ti(2) is bonded to one O(5), one O(6), one O(7), and two equivalent O(8) atoms to form corner-sharing TiO5 trigonal bipyramids. In the third Ti site, Ti(3) is bonded to one O(1), one O(5), one O(6), and two equivalent O(10) atoms to form a mixture of distorted corner and edge-sharing TiO5 trigonal bipyramids. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 2-coordinate geometry to one O(4) and one O(9) atom. In the second Tl site, Tl(2) is bonded in a 3-coordinate geometry to one O(2) and two equivalent O(4) atoms. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ba(2), one Ti(3), and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ba(2), one Ti(1), and one Tl(2) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ba(2) and one Ti(1) atom. In the fourth O site, O(4) is bonded to one Ba(2), one Tl(1), and two equivalent Tl(2) atoms to form corner-sharing OBaTl3 tetrahedra. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Ti(2) and one Ti(3) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ba(1), one Ti(2), and one Ti(3) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ba(1), one Mg(1), and one Ti(2) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to two equivalent Ba(1) and two equivalent Ti(2) atoms. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), two equivalent Mg(1), and one Tl(1) atom. In the tenth O site, O(10) is bonded in a distorted T-shaped geometry to one Ti(1) and two equivalent Ti(3) atoms.
Ba2MgTi3Tl2O10 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), two equivalent O(7), and two equivalent O(8) atoms. The Ba(1)-O(9) bond length is 2.76 Å. Both Ba(1)-O(6) bond lengths are 2.77 Å. Both Ba(1)-O(7) bond lengths are 2.68 Å. There is one shorter (2.76 Å) and one longer (3.04 Å) Ba(1)-O(8) bond length. In the second Ba site, Ba(2) is bonded in a 6-coordinate geometry to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms. The Ba(2)-O(1) bond length is 2.87 Å. The Ba(2)-O(4) bond length is 2.69 Å. There is one shorter (2.68 Å) and one longer (2.69 Å) Ba(2)-O(2) bond length. Both Ba(2)-O(3) bond lengths are 2.63 Å. Mg(1) is bonded in a distorted trigonal non-coplanar geometry to one O(7) and two equivalent O(9) atoms. The Mg(1)-O(7) bond length is 1.96 Å. There is one shorter (2.04 Å) and one longer (2.05 Å) Mg(1)-O(9) bond length. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(10), one O(2), one O(3), and two equivalent O(1) atoms to form a mixture of distorted corner and edge-sharing TiO5 trigonal bipyramids. The Ti(1)-O(10) bond length is 2.09 Å. The Ti(1)-O(2) bond length is 1.86 Å. The Ti(1)-O(3) bond length is 1.74 Å. Both Ti(1)-O(1) bond lengths are 1.99 Å. In the second Ti site, Ti(2) is bonded to one O(5), one O(6), one O(7), and two equivalent O(8) atoms to form corner-sharing TiO5 trigonal bipyramids. The Ti(2)-O(5) bond length is 1.93 Å. The Ti(2)-O(6) bond length is 1.84 Å. The Ti(2)-O(7) bond length is 2.00 Å. There is one shorter (1.93 Å) and one longer (1.95 Å) Ti(2)-O(8) bond length. In the third Ti site, Ti(3) is bonded to one O(1), one O(5), one O(6), and two equivalent O(10) atoms to form a mixture of distorted corner and edge-sharing TiO5 trigonal bipyramids. The Ti(3)-O(1) bond length is 1.99 Å. The Ti(3)-O(5) bond length is 1.76 Å. The Ti(3)-O(6) bond length is 2.00 Å. Both Ti(3)-O(10) bond lengths are 1.95 Å. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 2-coordinate geometry to one O(4) and one O(9) atom. The Tl(1)-O(4) bond length is 2.23 Å. The Tl(1)-O(9) bond length is 2.61 Å. In the second Tl site, Tl(2) is bonded in a 3-coordinate geometry to one O(2) and two equivalent O(4) atoms. The Tl(2)-O(2) bond length is 2.63 Å. There is one shorter (2.41 Å) and one longer (2.43 Å) Tl(2)-O(4) bond length. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ba(2), one Ti(3), and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ba(2), one Ti(1), and one Tl(2) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ba(2) and one Ti(1) atom. In the fourth O site, O(4) is bonded to one Ba(2), one Tl(1), and two equivalent Tl(2) atoms to form corner-sharing OBaTl3 tetrahedra. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Ti(2) and one Ti(3) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ba(1), one Ti(2), and one Ti(3) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ba(1), one Mg(1), and one Ti(2) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to two equivalent Ba(1) and two equivalent Ti(2) atoms. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), two equivalent Mg(1), and one Tl(1) atom. In the tenth O site, O(10) is bonded in a distorted T-shaped geometry to one Ti(1) and two equivalent Ti(3) atoms.