Tl4Bi is beta-derived structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 12-coordinate geometry to three equivalent Tl(2), six equivalent Tl(1), and three equivalent Bi(1) atoms. In the second Tl site, Tl(2) is bonded to three equivalent Tl(1) and nine equivalent Tl(2) atoms to form TlTl12 cuboctahedra that share corners with three equivalent Bi(1)Tl6Bi6 cuboctahedra, corners with six equivalent Tl(2)Tl12 cuboctahedra, edges with three equivalent Bi(1)Tl6Bi6 cuboctahedra, edges with twelve equivalent Tl(2)Tl12 cuboctahedra, and faces with twelve equivalent Tl(2)Tl12 cuboctahedra. Bi(1) is bonded to six equivalent Tl(1) and six equivalent Bi(1) atoms to form BiTl6Bi6 cuboctahedra that share corners with six equivalent Tl(2)Tl12 cuboctahedra, corners with six equivalent Bi(1)Tl6Bi6 cuboctahedra, edges with six equivalent Tl(2)Tl12 cuboctahedra, edges with six equivalent Bi(1)Tl6Bi6 cuboctahedra, and faces with six equivalent Bi(1)Tl6Bi6 cuboctahedra.
Tl4Bi is beta-derived structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 12-coordinate geometry to three equivalent Tl(2), six equivalent Tl(1), and three equivalent Bi(1) atoms. All Tl(1)-Tl(2) bond lengths are 3.60 Å. All Tl(1)-Tl(1) bond lengths are 3.50 Å. All Tl(1)-Bi(1) bond lengths are 3.59 Å. In the second Tl site, Tl(2) is bonded to three equivalent Tl(1) and nine equivalent Tl(2) atoms to form TlTl12 cuboctahedra that share corners with three equivalent Bi(1)Tl6Bi6 cuboctahedra, corners with six equivalent Tl(2)Tl12 cuboctahedra, edges with three equivalent Bi(1)Tl6Bi6 cuboctahedra, edges with twelve equivalent Tl(2)Tl12 cuboctahedra, and faces with twelve equivalent Tl(2)Tl12 cuboctahedra. There are six shorter (3.50 Å) and three longer (3.62 Å) Tl(2)-Tl(2) bond lengths. Bi(1) is bonded to six equivalent Tl(1) and six equivalent Bi(1) atoms to form BiTl6Bi6 cuboctahedra that share corners with six equivalent Tl(2)Tl12 cuboctahedra, corners with six equivalent Bi(1)Tl6Bi6 cuboctahedra, edges with six equivalent Tl(2)Tl12 cuboctahedra, edges with six equivalent Bi(1)Tl6Bi6 cuboctahedra, and faces with six equivalent Bi(1)Tl6Bi6 cuboctahedra. All Bi(1)-Bi(1) bond lengths are 3.50 Å.