Ba2Ti2TlAlO7 crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 5-coordinate geometry to one O(5) and four equivalent O(1) atoms. In the second Ba site, Ba(2) is bonded in a 5-coordinate geometry to one O(5) and four equivalent O(7) atoms. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted corner-sharing TiO5 trigonal bipyramids. In the second Ti site, Ti(2) is bonded to one O(7), two equivalent O(4), and two equivalent O(6) atoms to form distorted corner-sharing TiO5 trigonal bipyramids. Tl(1) is bonded in a T-shaped geometry to three equivalent O(5) atoms. Al(1) is bonded in a square co-planar geometry to one O(2), one O(3), one O(4), and one O(6) atom. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to four equivalent Ba(1) and one Ti(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to two equivalent Ti(1) and one Al(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to two equivalent Ti(1) and one Al(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to two equivalent Ti(2) and one Al(1) atom. In the fifth O site, O(5) is bonded to one Ba(1), one Ba(2), and three equivalent Tl(1) atoms to form distorted corner-sharing OBa2Tl3 square pyramids. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to two equivalent Ti(2) and one Al(1) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to four equivalent Ba(2) and one Ti(2) atom.
Ba2Ti2TlAlO7 crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 5-coordinate geometry to one O(5) and four equivalent O(1) atoms. The Ba(1)-O(5) bond length is 2.46 Å. There are a spread of Ba(1)-O(1) bond distances ranging from 2.92-3.04 Å. In the second Ba site, Ba(2) is bonded in a 5-coordinate geometry to one O(5) and four equivalent O(7) atoms. The Ba(2)-O(5) bond length is 2.49 Å. There are a spread of Ba(2)-O(7) bond distances ranging from 2.94-3.14 Å. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted corner-sharing TiO5 trigonal bipyramids. The Ti(1)-O(1) bond length is 1.77 Å. There is one shorter (1.99 Å) and one longer (2.06 Å) Ti(1)-O(2) bond length. There is one shorter (1.99 Å) and one longer (2.05 Å) Ti(1)-O(3) bond length. In the second Ti site, Ti(2) is bonded to one O(7), two equivalent O(4), and two equivalent O(6) atoms to form distorted corner-sharing TiO5 trigonal bipyramids. The Ti(2)-O(7) bond length is 1.77 Å. There is one shorter (2.00 Å) and one longer (2.04 Å) Ti(2)-O(4) bond length. There is one shorter (2.00 Å) and one longer (2.06 Å) Ti(2)-O(6) bond length. Tl(1) is bonded in a T-shaped geometry to three equivalent O(5) atoms. There are a spread of Tl(1)-O(5) bond distances ranging from 2.64-2.67 Å. Al(1) is bonded in a square co-planar geometry to one O(2), one O(3), one O(4), and one O(6) atom. The Al(1)-O(2) bond length is 1.87 Å. The Al(1)-O(3) bond length is 1.85 Å. The Al(1)-O(4) bond length is 1.86 Å. The Al(1)-O(6) bond length is 1.87 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to four equivalent Ba(1) and one Ti(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to two equivalent Ti(1) and one Al(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to two equivalent Ti(1) and one Al(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to two equivalent Ti(2) and one Al(1) atom. In the fifth O site, O(5) is bonded to one Ba(1), one Ba(2), and three equivalent Tl(1) atoms to form distorted corner-sharing OBa2Tl3 square pyramids. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to two equivalent Ti(2) and one Al(1) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to four equivalent Ba(2) and one Ti(2) atom.