Ba2Zn3Tl2(CuO3)4 crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded in a 9-coordinate geometry to one O(3), four equivalent O(1), and four equivalent O(4) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to four equivalent O(2) atoms. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to four equivalent O(1) atoms. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. In the second Zn site, Zn(2) is bonded in a body-centered cubic geometry to eight equivalent O(2) atoms. Tl(1) is bonded to one O(4) and five equivalent O(3) atoms to form a mixture of distorted corner and edge-sharing TlO6 octahedra. The corner-sharing octahedral tilt angles are 7°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ba(1), two equivalent Cu(2), and two equivalent Zn(1) atoms to form distorted OBa2Zn2Cu2 octahedra that share corners with two equivalent O(1)Ba2Zn2Cu2 octahedra, corners with two equivalent O(3)BaTl5 octahedra, corners with six equivalent O(2)Zn4Cu2 octahedra,  an edgeedge with one O(2)Zn4Cu2 octahedra, edges with two equivalent O(1)Ba2Zn2Cu2 octahedra, and faces with four equivalent O(1)Ba2Zn2Cu2 octahedra. The corner-sharing octahedral tilt angles range from 1-69°. In the second O site, O(2) is bonded to two equivalent Cu(1), two equivalent Zn(1), and two equivalent Zn(2) atoms to form distorted OZn4Cu2 octahedra that share corners with six equivalent O(1)Ba2Zn2Cu2 octahedra, corners with eight equivalent O(2)Zn4Cu2 octahedra,  an edgeedge with one O(1)Ba2Zn2Cu2 octahedra, edges with three equivalent O(2)Zn4Cu2 octahedra, and faces with four equivalent O(2)Zn4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-69°. In the third O site, O(3) is bonded to one Ba(1) and five equivalent Tl(1) atoms to form distorted OBaTl5 octahedra that share corners with four equivalent O(1)Ba2Zn2Cu2 octahedra, corners with four equivalent O(3)BaTl5 octahedra, and edges with eight equivalent O(3)BaTl5 octahedra. The corner-sharing octahedral tilt angles range from 7-43°. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to four equivalent Ba(1) and one Tl(1) atom.
Ba2Zn3Tl2(CuO3)4 crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded in a 9-coordinate geometry to one O(3), four equivalent O(1), and four equivalent O(4) atoms. The Ba(1)-O(3) bond length is 3.02 Å. All Ba(1)-O(1) bond lengths are 2.81 Å. All Ba(1)-O(4) bond lengths are 2.82 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to four equivalent O(2) atoms. All Cu(1)-O(2) bond lengths are 1.91 Å. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to four equivalent O(1) atoms. All Cu(2)-O(1) bond lengths are 1.91 Å. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. All Zn(1)-O(1) bond lengths are 2.31 Å. All Zn(1)-O(2) bond lengths are 2.49 Å. In the second Zn site, Zn(2) is bonded in a body-centered cubic geometry to eight equivalent O(2) atoms. All Zn(2)-O(2) bond lengths are 2.40 Å. Tl(1) is bonded to one O(4) and five equivalent O(3) atoms to form a mixture of distorted corner and edge-sharing TlO6 octahedra. The corner-sharing octahedral tilt angles are 7°. The Tl(1)-O(4) bond length is 2.07 Å. There is one shorter (2.12 Å) and four longer (2.71 Å) Tl(1)-O(3) bond lengths. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ba(1), two equivalent Cu(2), and two equivalent Zn(1) atoms to form distorted OBa2Zn2Cu2 octahedra that share corners with two equivalent O(1)Ba2Zn2Cu2 octahedra, corners with two equivalent O(3)BaTl5 octahedra, corners with six equivalent O(2)Zn4Cu2 octahedra,  an edgeedge with one O(2)Zn4Cu2 octahedra, edges with two equivalent O(1)Ba2Zn2Cu2 octahedra, and faces with four equivalent O(1)Ba2Zn2Cu2 octahedra. The corner-sharing octahedral tilt angles range from 1-69°. In the second O site, O(2) is bonded to two equivalent Cu(1), two equivalent Zn(1), and two equivalent Zn(2) atoms to form distorted OZn4Cu2 octahedra that share corners with six equivalent O(1)Ba2Zn2Cu2 octahedra, corners with eight equivalent O(2)Zn4Cu2 octahedra,  an edgeedge with one O(1)Ba2Zn2Cu2 octahedra, edges with three equivalent O(2)Zn4Cu2 octahedra, and faces with four equivalent O(2)Zn4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-69°. In the third O site, O(3) is bonded to one Ba(1) and five equivalent Tl(1) atoms to form distorted OBaTl5 octahedra that share corners with four equivalent O(1)Ba2Zn2Cu2 octahedra, corners with four equivalent O(3)BaTl5 octahedra, and edges with eight equivalent O(3)BaTl5 octahedra. The corner-sharing octahedral tilt angles range from 7-43°. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to four equivalent Ba(1) and one Tl(1) atom.