Be2ZnTl2(O3F4)2 crystallizes in the monoclinic P2_1/c space group. Be(1) is bonded to one F(1), one F(2), one F(3), and one F(4) atom to form BeF4 tetrahedra that share  a cornercorner with one Zn(1)O4F2 octahedra. The corner-sharing octahedral tilt angles are 40°. Zn(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent F(3) atoms to form ZnO4F2 octahedra that share corners with two equivalent Be(1)F4 tetrahedra. Tl(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one F(1), one F(2), and one F(4) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Tl(1) and one O(2) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Zn(1), one Tl(1), and one O(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Zn(1) and one O(3) atom. There are four inequivalent F sites. In the first F site, F(4) is bonded in a single-bond geometry to one Be(1) and one Tl(1) atom. In the second F site, F(1) is bonded in a distorted bent 150 degrees geometry to one Be(1) and one Tl(1) atom. In the third F site, F(2) is bonded in a water-like geometry to one Be(1) and one Tl(1) atom. In the fourth F site, F(3) is bonded in a bent 150 degrees geometry to one Be(1) and one Zn(1) atom.
Be2ZnTl2(O3F4)2 crystallizes in the monoclinic P2_1/c space group. Be(1) is bonded to one F(1), one F(2), one F(3), and one F(4) atom to form BeF4 tetrahedra that share  a cornercorner with one Zn(1)O4F2 octahedra. The corner-sharing octahedral tilt angles are 40°. The Be(1)-F(1) bond length is 1.56 Å. The Be(1)-F(2) bond length is 1.60 Å. The Be(1)-F(3) bond length is 1.59 Å. The Be(1)-F(4) bond length is 1.57 Å. Zn(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent F(3) atoms to form ZnO4F2 octahedra that share corners with two equivalent Be(1)F4 tetrahedra. Both Zn(1)-O(2) bond lengths are 2.08 Å. Both Zn(1)-O(3) bond lengths are 2.29 Å. Both Zn(1)-F(3) bond lengths are 2.01 Å. Tl(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one F(1), one F(2), and one F(4) atom. The Tl(1)-O(1) bond length is 2.23 Å. The Tl(1)-O(2) bond length is 2.33 Å. The Tl(1)-F(1) bond length is 2.29 Å. The Tl(1)-F(2) bond length is 2.25 Å. The Tl(1)-F(4) bond length is 2.59 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Tl(1) and one O(2) atom. The O(1)-O(2) bond length is 1.37 Å. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Zn(1), one Tl(1), and one O(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Zn(1) and one O(3) atom. The O(3)-O(3) bond length is 1.25 Å. There are four inequivalent F sites. In the first F site, F(4) is bonded in a single-bond geometry to one Be(1) and one Tl(1) atom. In the second F site, F(1) is bonded in a distorted bent 150 degrees geometry to one Be(1) and one Tl(1) atom. In the third F site, F(2) is bonded in a water-like geometry to one Be(1) and one Tl(1) atom. In the fourth F site, F(3) is bonded in a bent 150 degrees geometry to one Be(1) and one Zn(1) atom.