ErTl3 is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. Er(1) is bonded to twelve equivalent Tl(1) atoms to form ErTl12 cuboctahedra that share corners with twelve equivalent Er(1)Tl12 cuboctahedra, edges with twenty-four equivalent Tl(1)Er4Tl8 cuboctahedra, faces with six equivalent Er(1)Tl12 cuboctahedra, and faces with twelve equivalent Tl(1)Er4Tl8 cuboctahedra. Tl(1) is bonded to four equivalent Er(1) and eight equivalent Tl(1) atoms to form TlEr4Tl8 cuboctahedra that share corners with twelve equivalent Tl(1)Er4Tl8 cuboctahedra, edges with eight equivalent Er(1)Tl12 cuboctahedra, edges with sixteen equivalent Tl(1)Er4Tl8 cuboctahedra, faces with four equivalent Er(1)Tl12 cuboctahedra, and faces with fourteen equivalent Tl(1)Er4Tl8 cuboctahedra.
ErTl3 is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. Er(1) is bonded to twelve equivalent Tl(1) atoms to form ErTl12 cuboctahedra that share corners with twelve equivalent Er(1)Tl12 cuboctahedra, edges with twenty-four equivalent Tl(1)Er4Tl8 cuboctahedra, faces with six equivalent Er(1)Tl12 cuboctahedra, and faces with twelve equivalent Tl(1)Er4Tl8 cuboctahedra. All Er(1)-Tl(1) bond lengths are 3.32 Å. Tl(1) is bonded to four equivalent Er(1) and eight equivalent Tl(1) atoms to form TlEr4Tl8 cuboctahedra that share corners with twelve equivalent Tl(1)Er4Tl8 cuboctahedra, edges with eight equivalent Er(1)Tl12 cuboctahedra, edges with sixteen equivalent Tl(1)Er4Tl8 cuboctahedra, faces with four equivalent Er(1)Tl12 cuboctahedra, and faces with fourteen equivalent Tl(1)Er4Tl8 cuboctahedra. All Tl(1)-Tl(1) bond lengths are 3.32 Å.