MgTl3 is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Tl(1) and eight equivalent Tl(2) atoms to form MgTl12 cuboctahedra that share corners with four equivalent Mg(1)Tl12 cuboctahedra, corners with eight equivalent Tl(1)Mg4Tl8 cuboctahedra, edges with eight equivalent Mg(1)Tl12 cuboctahedra, edges with sixteen equivalent Tl(2)Mg4Tl8 cuboctahedra, faces with four equivalent Mg(1)Tl12 cuboctahedra, faces with six equivalent Tl(1)Mg4Tl8 cuboctahedra, and faces with eight equivalent Tl(2)Mg4Tl8 cuboctahedra. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded to four equivalent Mg(1) and eight equivalent Tl(2) atoms to form distorted TlMg4Tl8 cuboctahedra that share corners with four equivalent Tl(1)Mg4Tl8 cuboctahedra, corners with eight equivalent Mg(1)Tl12 cuboctahedra, edges with eight equivalent Tl(1)Mg4Tl8 cuboctahedra, edges with sixteen equivalent Tl(2)Mg4Tl8 cuboctahedra, faces with four equivalent Tl(1)Mg4Tl8 cuboctahedra, faces with six equivalent Mg(1)Tl12 cuboctahedra, and faces with eight equivalent Tl(2)Mg4Tl8 cuboctahedra. In the second Tl site, Tl(2) is bonded to four equivalent Mg(1), four equivalent Tl(1), and four equivalent Tl(2) atoms to form TlMg4Tl8 cuboctahedra that share corners with twelve equivalent Tl(2)Mg4Tl8 cuboctahedra, edges with eight equivalent Mg(1)Tl12 cuboctahedra, edges with eight equivalent Tl(1)Mg4Tl8 cuboctahedra, edges with eight equivalent Tl(2)Mg4Tl8 cuboctahedra, faces with four equivalent Mg(1)Tl12 cuboctahedra, faces with four equivalent Tl(1)Mg4Tl8 cuboctahedra, and faces with ten equivalent Tl(2)Mg4Tl8 cuboctahedra.
MgTl3 is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Tl(1) and eight equivalent Tl(2) atoms to form MgTl12 cuboctahedra that share corners with four equivalent Mg(1)Tl12 cuboctahedra, corners with eight equivalent Tl(1)Mg4Tl8 cuboctahedra, edges with eight equivalent Mg(1)Tl12 cuboctahedra, edges with sixteen equivalent Tl(2)Mg4Tl8 cuboctahedra, faces with four equivalent Mg(1)Tl12 cuboctahedra, faces with six equivalent Tl(1)Mg4Tl8 cuboctahedra, and faces with eight equivalent Tl(2)Mg4Tl8 cuboctahedra. All Mg(1)-Tl(1) bond lengths are 3.29 Å. All Mg(1)-Tl(2) bond lengths are 3.43 Å. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded to four equivalent Mg(1) and eight equivalent Tl(2) atoms to form distorted TlMg4Tl8 cuboctahedra that share corners with four equivalent Tl(1)Mg4Tl8 cuboctahedra, corners with eight equivalent Mg(1)Tl12 cuboctahedra, edges with eight equivalent Tl(1)Mg4Tl8 cuboctahedra, edges with sixteen equivalent Tl(2)Mg4Tl8 cuboctahedra, faces with four equivalent Tl(1)Mg4Tl8 cuboctahedra, faces with six equivalent Mg(1)Tl12 cuboctahedra, and faces with eight equivalent Tl(2)Mg4Tl8 cuboctahedra. All Tl(1)-Tl(2) bond lengths are 3.43 Å. In the second Tl site, Tl(2) is bonded to four equivalent Mg(1), four equivalent Tl(1), and four equivalent Tl(2) atoms to form TlMg4Tl8 cuboctahedra that share corners with twelve equivalent Tl(2)Mg4Tl8 cuboctahedra, edges with eight equivalent Mg(1)Tl12 cuboctahedra, edges with eight equivalent Tl(1)Mg4Tl8 cuboctahedra, edges with eight equivalent Tl(2)Mg4Tl8 cuboctahedra, faces with four equivalent Mg(1)Tl12 cuboctahedra, faces with four equivalent Tl(1)Mg4Tl8 cuboctahedra, and faces with ten equivalent Tl(2)Mg4Tl8 cuboctahedra. All Tl(2)-Tl(2) bond lengths are 3.29 Å.