Tl2Ba2CuO6 crystallizes in the orthorhombic Cmce space group. Ba(1) is bonded in a 9-coordinate geometry to one O(1), four equivalent O(2), and four equivalent O(3) atoms. Cu(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. Tl(1) is bonded to one O(2) and four equivalent O(1) atoms to form a mixture of distorted edge and corner-sharing TlO5 square pyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Ba(1) and four equivalent Tl(1) atoms to form distorted OBaTl4 square pyramids that share corners with four equivalent O(3)Ba4Cu2 octahedra, corners with four equivalent O(1)BaTl4 square pyramids, and edges with four equivalent O(1)BaTl4 square pyramids. The corner-sharing octahedral tilt angles range from 42-49°. In the second O site, O(2) is bonded in a 5-coordinate geometry to four equivalent Ba(1) and one Tl(1) atom. In the third O site, O(3) is bonded to four equivalent Ba(1) and two equivalent Cu(1) atoms to form distorted OBa4Cu2 octahedra that share corners with two equivalent O(3)Ba4Cu2 octahedra, corners with four equivalent O(1)BaTl4 square pyramids, edges with two equivalent O(3)Ba4Cu2 octahedra, and faces with four equivalent O(3)Ba4Cu2 octahedra. The corner-sharing octahedra are not tilted.
Tl2Ba2CuO6 crystallizes in the orthorhombic Cmce space group. Ba(1) is bonded in a 9-coordinate geometry to one O(1), four equivalent O(2), and four equivalent O(3) atoms. The Ba(1)-O(1) bond length is 3.14 Å. There are two shorter (2.88 Å) and two longer (2.92 Å) Ba(1)-O(2) bond lengths. All Ba(1)-O(3) bond lengths are 2.76 Å. Cu(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. All Cu(1)-O(3) bond lengths are 1.96 Å. Tl(1) is bonded to one O(2) and four equivalent O(1) atoms to form a mixture of distorted edge and corner-sharing TlO5 square pyramids. The Tl(1)-O(2) bond length is 2.04 Å. There are a spread of Tl(1)-O(1) bond distances ranging from 2.09-2.77 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Ba(1) and four equivalent Tl(1) atoms to form distorted OBaTl4 square pyramids that share corners with four equivalent O(3)Ba4Cu2 octahedra, corners with four equivalent O(1)BaTl4 square pyramids, and edges with four equivalent O(1)BaTl4 square pyramids. The corner-sharing octahedral tilt angles range from 42-49°. In the second O site, O(2) is bonded in a 5-coordinate geometry to four equivalent Ba(1) and one Tl(1) atom. In the third O site, O(3) is bonded to four equivalent Ba(1) and two equivalent Cu(1) atoms to form distorted OBa4Cu2 octahedra that share corners with two equivalent O(3)Ba4Cu2 octahedra, corners with four equivalent O(1)BaTl4 square pyramids, edges with two equivalent O(3)Ba4Cu2 octahedra, and faces with four equivalent O(3)Ba4Cu2 octahedra. The corner-sharing octahedra are not tilted.