Tl3In crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a distorted body-centered cubic geometry to two equivalent Tl(2), four equivalent Tl(1), and two equivalent In(1) atoms. In the second Tl site, Tl(2) is bonded in a body-centered cubic geometry to four equivalent Tl(1) and four equivalent Tl(2) atoms. In(1) is bonded in a body-centered cubic geometry to four equivalent Tl(1) and four equivalent In(1) atoms.
Tl3In crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a distorted body-centered cubic geometry to two equivalent Tl(2), four equivalent Tl(1), and two equivalent In(1) atoms. Both Tl(1)-Tl(2) bond lengths are 3.45 Å. All Tl(1)-Tl(1) bond lengths are 3.35 Å. Both Tl(1)-In(1) bond lengths are 3.29 Å. In the second Tl site, Tl(2) is bonded in a body-centered cubic geometry to four equivalent Tl(1) and four equivalent Tl(2) atoms. All Tl(2)-Tl(2) bond lengths are 3.35 Å. In(1) is bonded in a body-centered cubic geometry to four equivalent Tl(1) and four equivalent In(1) atoms. All In(1)-In(1) bond lengths are 3.35 Å.