Tl2Ba2O5 crystallizes in the orthorhombic Pnma space group. Ba(1) is bonded in a 8-coordinate geometry to one O(1), three equivalent O(2), and four equivalent O(3) atoms. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form TlO6 octahedra that share corners with four equivalent Tl(1)O6 octahedra and corners with two equivalent Tl(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 11°. In the second Tl site, Tl(2) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form TlO4 tetrahedra that share corners with two equivalent Tl(1)O6 octahedra and corners with two equivalent Tl(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 33°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ba(1) and two equivalent Tl(2) atoms to form distorted corner-sharing OBa2Tl2 tetrahedra. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent Ba(1), one Tl(1), and one Tl(2) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to four equivalent Ba(1) and two equivalent Tl(1) atoms.
Tl2Ba2O5 crystallizes in the orthorhombic Pnma space group. Ba(1) is bonded in a 8-coordinate geometry to one O(1), three equivalent O(2), and four equivalent O(3) atoms. The Ba(1)-O(1) bond length is 2.66 Å. There are a spread of Ba(1)-O(2) bond distances ranging from 2.71-3.33 Å. There are a spread of Ba(1)-O(3) bond distances ranging from 2.82-3.05 Å. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form TlO6 octahedra that share corners with four equivalent Tl(1)O6 octahedra and corners with two equivalent Tl(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 11°. Both Tl(1)-O(2) bond lengths are 2.44 Å. There are two shorter (2.08 Å) and two longer (2.33 Å) Tl(1)-O(3) bond lengths. In the second Tl site, Tl(2) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form TlO4 tetrahedra that share corners with two equivalent Tl(1)O6 octahedra and corners with two equivalent Tl(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 33°. There is one shorter (2.23 Å) and one longer (2.25 Å) Tl(2)-O(1) bond length. Both Tl(2)-O(2) bond lengths are 2.11 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ba(1) and two equivalent Tl(2) atoms to form distorted corner-sharing OBa2Tl2 tetrahedra. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent Ba(1), one Tl(1), and one Tl(2) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to four equivalent Ba(1) and two equivalent Tl(1) atoms.