KTl crystallizes in the orthorhombic Cmce space group. There are three inequivalent K sites. In the first K site, K(1) is bonded to four equivalent Tl(2) atoms to form distorted edge-sharing KTl4 tetrahedra. In the second K site, K(2) is bonded in a 6-coordinate geometry to two equivalent Tl(1) and four equivalent Tl(2) atoms. In the third K site, K(3) is bonded in a 5-coordinate geometry to two equivalent Tl(1) and four equivalent Tl(2) atoms. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 8-coordinate geometry to two equivalent K(2), two equivalent K(3), and four equivalent Tl(2) atoms. In the second Tl site, Tl(2) is bonded in a 10-coordinate geometry to two equivalent K(1), two equivalent K(2), two equivalent K(3), two equivalent Tl(1), and two equivalent Tl(2) atoms.
KTl crystallizes in the orthorhombic Cmce space group. There are three inequivalent K sites. In the first K site, K(1) is bonded to four equivalent Tl(2) atoms to form distorted edge-sharing KTl4 tetrahedra. There are two shorter (3.70 Å) and two longer (3.75 Å) K(1)-Tl(2) bond lengths. In the second K site, K(2) is bonded in a 6-coordinate geometry to two equivalent Tl(1) and four equivalent Tl(2) atoms. Both K(2)-Tl(1) bond lengths are 3.65 Å. There are two shorter (3.66 Å) and two longer (4.00 Å) K(2)-Tl(2) bond lengths. In the third K site, K(3) is bonded in a 5-coordinate geometry to two equivalent Tl(1) and four equivalent Tl(2) atoms. There is one shorter (3.79 Å) and one longer (4.01 Å) K(3)-Tl(1) bond length. There are two shorter (3.62 Å) and two longer (3.69 Å) K(3)-Tl(2) bond lengths. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 8-coordinate geometry to two equivalent K(2), two equivalent K(3), and four equivalent Tl(2) atoms. There are two shorter (3.08 Å) and two longer (3.10 Å) Tl(1)-Tl(2) bond lengths. In the second Tl site, Tl(2) is bonded in a 10-coordinate geometry to two equivalent K(1), two equivalent K(2), two equivalent K(3), two equivalent Tl(1), and two equivalent Tl(2) atoms. There is one shorter (3.43 Å) and one longer (3.55 Å) Tl(2)-Tl(2) bond length.