MgTl4Al4O12 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(3), one O(6), and one O(8) atom. There are four inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a rectangular see-saw-like geometry to one O(2), one O(4), one O(5), and one O(7) atom. In the second Tl site, Tl(2) is bonded in a 6-coordinate geometry to one O(12), one O(2), one O(3), one O(4), one O(5), and one O(8) atom. In the third Tl site, Tl(3) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(5), one O(6), and one O(9) atom. In the fourth Tl site, Tl(4) is bonded in a 4-coordinate geometry to one O(1), one O(10), one O(11), and one O(4) atom. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(10), one O(12), one O(3), and one O(8) atom to form AlO4 tetrahedra that share  a cornercorner with one Al(2)O5 square pyramid and corners with two equivalent Al(3)O4 tetrahedra. In the second Al site, Al(2) is bonded to one O(1), one O(11), one O(12), one O(5), and one O(9) atom to form AlO5 square pyramids that share  a cornercorner with one Al(1)O4 tetrahedra and corners with two equivalent Al(4)O5 trigonal bipyramids. In the third Al site, Al(3) is bonded to one O(10), one O(4), one O(7), and one O(8) atom to form AlO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra and  a cornercorner with one Al(4)O5 trigonal bipyramid. In the fourth Al site, Al(4) is bonded to one O(11), one O(2), one O(6), one O(7), and one O(9) atom to form distorted AlO5 trigonal bipyramids that share corners with two equivalent Al(2)O5 square pyramids and  a cornercorner with one Al(3)O4 tetrahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Tl(3), one Tl(4), and one Al(2) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Tl(1), one Tl(2), and one Al(4) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Tl(2), and one Al(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Tl(1), one Tl(2), one Tl(4), and one Al(3) atom. In the fifth O site, O(5) is bonded to one Tl(1), one Tl(2), one Tl(3), and one Al(2) atom to form distorted corner-sharing OAlTl3 tetrahedra. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mg(1), one Tl(3), and one Al(4) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Tl(1), one Al(3), and one Al(4) atom. In the eighth O site, O(8) is bonded to one Mg(1), one Tl(2), one Al(1), and one Al(3) atom to form distorted corner-sharing OMgAl2Tl trigonal pyramids. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Tl(3), one Al(2), and one Al(4) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Tl(4), one Al(1), and one Al(3) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one Tl(3), one Tl(4), one Al(2), and one Al(4) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Tl(2), one Al(1), and one Al(2) atom.
MgTl4Al4O12 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(3), one O(6), and one O(8) atom. The Mg(1)-O(1) bond length is 1.98 Å. The Mg(1)-O(3) bond length is 2.08 Å. The Mg(1)-O(6) bond length is 1.99 Å. The Mg(1)-O(8) bond length is 2.11 Å. There are four inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a rectangular see-saw-like geometry to one O(2), one O(4), one O(5), and one O(7) atom. The Tl(1)-O(2) bond length is 2.11 Å. The Tl(1)-O(4) bond length is 2.24 Å. The Tl(1)-O(5) bond length is 2.21 Å. The Tl(1)-O(7) bond length is 2.10 Å. In the second Tl site, Tl(2) is bonded in a 6-coordinate geometry to one O(12), one O(2), one O(3), one O(4), one O(5), and one O(8) atom. The Tl(2)-O(12) bond length is 2.34 Å. The Tl(2)-O(2) bond length is 2.23 Å. The Tl(2)-O(3) bond length is 2.30 Å. The Tl(2)-O(4) bond length is 2.36 Å. The Tl(2)-O(5) bond length is 2.28 Å. The Tl(2)-O(8) bond length is 2.63 Å. In the third Tl site, Tl(3) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(5), one O(6), and one O(9) atom. The Tl(3)-O(1) bond length is 2.13 Å. The Tl(3)-O(11) bond length is 2.22 Å. The Tl(3)-O(5) bond length is 2.36 Å. The Tl(3)-O(6) bond length is 2.23 Å. The Tl(3)-O(9) bond length is 2.57 Å. In the fourth Tl site, Tl(4) is bonded in a 4-coordinate geometry to one O(1), one O(10), one O(11), and one O(4) atom. The Tl(4)-O(1) bond length is 2.63 Å. The Tl(4)-O(10) bond length is 2.51 Å. The Tl(4)-O(11) bond length is 2.63 Å. The Tl(4)-O(4) bond length is 2.77 Å. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(10), one O(12), one O(3), and one O(8) atom to form AlO4 tetrahedra that share  a cornercorner with one Al(2)O5 square pyramid and corners with two equivalent Al(3)O4 tetrahedra. The Al(1)-O(10) bond length is 1.81 Å. The Al(1)-O(12) bond length is 1.79 Å. The Al(1)-O(3) bond length is 1.77 Å. The Al(1)-O(8) bond length is 1.86 Å. In the second Al site, Al(2) is bonded to one O(1), one O(11), one O(12), one O(5), and one O(9) atom to form AlO5 square pyramids that share  a cornercorner with one Al(1)O4 tetrahedra and corners with two equivalent Al(4)O5 trigonal bipyramids. The Al(2)-O(1) bond length is 2.03 Å. The Al(2)-O(11) bond length is 1.83 Å. The Al(2)-O(12) bond length is 1.92 Å. The Al(2)-O(5) bond length is 1.90 Å. The Al(2)-O(9) bond length is 1.84 Å. In the third Al site, Al(3) is bonded to one O(10), one O(4), one O(7), and one O(8) atom to form AlO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra and  a cornercorner with one Al(4)O5 trigonal bipyramid. The Al(3)-O(10) bond length is 1.80 Å. The Al(3)-O(4) bond length is 1.79 Å. The Al(3)-O(7) bond length is 1.78 Å. The Al(3)-O(8) bond length is 1.86 Å. In the fourth Al site, Al(4) is bonded to one O(11), one O(2), one O(6), one O(7), and one O(9) atom to form distorted AlO5 trigonal bipyramids that share corners with two equivalent Al(2)O5 square pyramids and  a cornercorner with one Al(3)O4 tetrahedra. The Al(4)-O(11) bond length is 1.89 Å. The Al(4)-O(2) bond length is 1.86 Å. The Al(4)-O(6) bond length is 1.88 Å. The Al(4)-O(7) bond length is 2.04 Å. The Al(4)-O(9) bond length is 1.79 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Tl(3), one Tl(4), and one Al(2) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Tl(1), one Tl(2), and one Al(4) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Tl(2), and one Al(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Tl(1), one Tl(2), one Tl(4), and one Al(3) atom. In the fifth O site, O(5) is bonded to one Tl(1), one Tl(2), one Tl(3), and one Al(2) atom to form distorted corner-sharing OAlTl3 tetrahedra. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mg(1), one Tl(3), and one Al(4) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Tl(1), one Al(3), and one Al(4) atom. In the eighth O site, O(8) is bonded to one Mg(1), one Tl(2), one Al(1), and one Al(3) atom to form distorted corner-sharing OMgAl2Tl trigonal pyramids. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Tl(3), one Al(2), and one Al(4) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Tl(4), one Al(1), and one Al(3) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one Tl(3), one Tl(4), one Al(2), and one Al(4) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Tl(2), one Al(1), and one Al(2) atom.