Tl4GeI6 crystallizes in the tetragonal P4/mnc space group. Tl(1) is bonded in a 4-coordinate geometry to two equivalent I(1) and two equivalent I(2) atoms. Ge(1) is bonded in an octahedral geometry to two equivalent I(1) and four equivalent I(2) atoms. There are two inequivalent I sites. In the first I site, I(1) is bonded to four equivalent Tl(1) and one Ge(1) atom to form distorted corner-sharing ITl4Ge square pyramids. In the second I site, I(2) is bonded in a 3-coordinate geometry to two equivalent Tl(1) and one Ge(1) atom.
Tl4GeI6 crystallizes in the tetragonal P4/mnc space group. Tl(1) is bonded in a 4-coordinate geometry to two equivalent I(1) and two equivalent I(2) atoms. Both Tl(1)-I(1) bond lengths are 3.55 Å. Both Tl(1)-I(2) bond lengths are 3.53 Å. Ge(1) is bonded in an octahedral geometry to two equivalent I(1) and four equivalent I(2) atoms. Both Ge(1)-I(1) bond lengths are 2.99 Å. All Ge(1)-I(2) bond lengths are 3.07 Å. There are two inequivalent I sites. In the first I site, I(1) is bonded to four equivalent Tl(1) and one Ge(1) atom to form distorted corner-sharing ITl4Ge square pyramids. In the second I site, I(2) is bonded in a 3-coordinate geometry to two equivalent Tl(1) and one Ge(1) atom.