Y3Tl5 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 10-coordinate geometry to two equivalent Tl(2), four equivalent Tl(1), and four equivalent Tl(3) atoms. In the second Y site, Y(2) is bonded in a 9-coordinate geometry to one Tl(2), four equivalent Tl(1), and four equivalent Tl(3) atoms. There are three inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 10-coordinate geometry to two equivalent Y(2), four equivalent Y(1), two equivalent Tl(2), and two equivalent Tl(3) atoms. In the second Tl site, Tl(2) is bonded in a 11-coordinate geometry to one Y(2), four equivalent Y(1), two equivalent Tl(3), and four equivalent Tl(1) atoms. In the third Tl site, Tl(3) is bonded in a 10-coordinate geometry to two equivalent Y(2), four equivalent Y(1), one Tl(2), one Tl(3), and two equivalent Tl(1) atoms.
Y3Tl5 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 10-coordinate geometry to two equivalent Tl(2), four equivalent Tl(1), and four equivalent Tl(3) atoms. Both Y(1)-Tl(2) bond lengths are 3.33 Å. There are two shorter (3.21 Å) and two longer (3.55 Å) Y(1)-Tl(1) bond lengths. There are two shorter (3.24 Å) and two longer (3.38 Å) Y(1)-Tl(3) bond lengths. In the second Y site, Y(2) is bonded in a 9-coordinate geometry to one Tl(2), four equivalent Tl(1), and four equivalent Tl(3) atoms. The Y(2)-Tl(2) bond length is 3.16 Å. There are two shorter (3.14 Å) and two longer (3.43 Å) Y(2)-Tl(1) bond lengths. There are two shorter (3.10 Å) and two longer (3.37 Å) Y(2)-Tl(3) bond lengths. There are three inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 10-coordinate geometry to two equivalent Y(2), four equivalent Y(1), two equivalent Tl(2), and two equivalent Tl(3) atoms. There is one shorter (3.21 Å) and one longer (3.29 Å) Tl(1)-Tl(2) bond length. Both Tl(1)-Tl(3) bond lengths are 3.13 Å. In the second Tl site, Tl(2) is bonded in a 11-coordinate geometry to one Y(2), four equivalent Y(1), two equivalent Tl(3), and four equivalent Tl(1) atoms. Both Tl(2)-Tl(3) bond lengths are 3.29 Å. In the third Tl site, Tl(3) is bonded in a 10-coordinate geometry to two equivalent Y(2), four equivalent Y(1), one Tl(2), one Tl(3), and two equivalent Tl(1) atoms. The Tl(3)-Tl(3) bond length is 3.27 Å.