K3Tl is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to four equivalent K(1), four equivalent K(2), and four equivalent Tl(1) atoms to form distorted KK8Tl4 cuboctahedra that share corners with twelve equivalent K(1)K8Tl4 cuboctahedra, edges with eight equivalent K(1)K8Tl4 cuboctahedra, edges with eight equivalent K(2)K8Tl4 cuboctahedra, edges with eight equivalent Tl(1)K12 cuboctahedra, faces with four equivalent K(2)K8Tl4 cuboctahedra, faces with four equivalent Tl(1)K12 cuboctahedra, and faces with ten equivalent K(1)K8Tl4 cuboctahedra. In the second K site, K(2) is bonded to eight equivalent K(1) and four equivalent Tl(1) atoms to form distorted KK8Tl4 cuboctahedra that share corners with four equivalent K(2)K8Tl4 cuboctahedra, corners with eight equivalent Tl(1)K12 cuboctahedra, edges with eight equivalent K(2)K8Tl4 cuboctahedra, edges with sixteen equivalent K(1)K8Tl4 cuboctahedra, faces with four equivalent K(2)K8Tl4 cuboctahedra, faces with six equivalent Tl(1)K12 cuboctahedra, and faces with eight equivalent K(1)K8Tl4 cuboctahedra. Tl(1) is bonded to four equivalent K(2) and eight equivalent K(1) atoms to form TlK12 cuboctahedra that share corners with four equivalent Tl(1)K12 cuboctahedra, corners with eight equivalent K(2)K8Tl4 cuboctahedra, edges with eight equivalent Tl(1)K12 cuboctahedra, edges with sixteen equivalent K(1)K8Tl4 cuboctahedra, faces with four equivalent Tl(1)K12 cuboctahedra, faces with six equivalent K(2)K8Tl4 cuboctahedra, and faces with eight equivalent K(1)K8Tl4 cuboctahedra.
K3Tl is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to four equivalent K(1), four equivalent K(2), and four equivalent Tl(1) atoms to form distorted KK8Tl4 cuboctahedra that share corners with twelve equivalent K(1)K8Tl4 cuboctahedra, edges with eight equivalent K(1)K8Tl4 cuboctahedra, edges with eight equivalent K(2)K8Tl4 cuboctahedra, edges with eight equivalent Tl(1)K12 cuboctahedra, faces with four equivalent K(2)K8Tl4 cuboctahedra, faces with four equivalent Tl(1)K12 cuboctahedra, and faces with ten equivalent K(1)K8Tl4 cuboctahedra. All K(1)-K(1) bond lengths are 4.18 Å. All K(1)-K(2) bond lengths are 4.15 Å. All K(1)-Tl(1) bond lengths are 4.15 Å. In the second K site, K(2) is bonded to eight equivalent K(1) and four equivalent Tl(1) atoms to form distorted KK8Tl4 cuboctahedra that share corners with four equivalent K(2)K8Tl4 cuboctahedra, corners with eight equivalent Tl(1)K12 cuboctahedra, edges with eight equivalent K(2)K8Tl4 cuboctahedra, edges with sixteen equivalent K(1)K8Tl4 cuboctahedra, faces with four equivalent K(2)K8Tl4 cuboctahedra, faces with six equivalent Tl(1)K12 cuboctahedra, and faces with eight equivalent K(1)K8Tl4 cuboctahedra. All K(2)-Tl(1) bond lengths are 4.18 Å. Tl(1) is bonded to four equivalent K(2) and eight equivalent K(1) atoms to form TlK12 cuboctahedra that share corners with four equivalent Tl(1)K12 cuboctahedra, corners with eight equivalent K(2)K8Tl4 cuboctahedra, edges with eight equivalent Tl(1)K12 cuboctahedra, edges with sixteen equivalent K(1)K8Tl4 cuboctahedra, faces with four equivalent Tl(1)K12 cuboctahedra, faces with six equivalent K(2)K8Tl4 cuboctahedra, and faces with eight equivalent K(1)K8Tl4 cuboctahedra.