U2(AlSn)3 crystallizes in the orthorhombic Pmmm space group. U(1) is bonded to two equivalent Al(2), four equivalent Al(1), two equivalent Sn(1), two equivalent Sn(2), and two equivalent Sn(3) atoms to form UAl6Sn6 cuboctahedra that share corners with twelve equivalent U(1)Al6Sn6 cuboctahedra, edges with four equivalent Al(2)U4Al4Sn4 cuboctahedra, edges with four equivalent Sn(1)U4Al4Sn4 cuboctahedra, edges with four equivalent Sn(3)U4Al4Sn4 cuboctahedra, edges with four equivalent Sn(2)U4Al8 cuboctahedra, edges with eight equivalent Al(1)U4Al2Sn6 cuboctahedra, faces with two equivalent Al(2)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(1)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(3)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(2)U4Al8 cuboctahedra, faces with four equivalent Al(1)U4Al2Sn6 cuboctahedra, and faces with six equivalent U(1)Al6Sn6 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent U(1), two equivalent Al(2), two equivalent Sn(1), two equivalent Sn(2), and two equivalent Sn(3) atoms to form distorted AlU4Al2Sn6 cuboctahedra that share corners with twelve equivalent Al(1)U4Al2Sn6 cuboctahedra, edges with four equivalent Al(2)U4Al4Sn4 cuboctahedra, edges with four equivalent Sn(1)U4Al4Sn4 cuboctahedra, edges with four equivalent Sn(3)U4Al4Sn4 cuboctahedra, edges with four equivalent Sn(2)U4Al8 cuboctahedra, edges with eight equivalent U(1)Al6Sn6 cuboctahedra, faces with two equivalent Al(2)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(1)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(3)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(2)U4Al8 cuboctahedra, faces with four equivalent U(1)Al6Sn6 cuboctahedra, and faces with six equivalent Al(1)U4Al2Sn6 cuboctahedra. In the second Al site, Al(2) is bonded to four equivalent U(1), four equivalent Al(1), and four equivalent Sn(2) atoms to form distorted AlU4Al4Sn4 cuboctahedra that share corners with four equivalent Al(2)U4Al4Sn4 cuboctahedra, corners with eight equivalent Sn(1)U4Al4Sn4 cuboctahedra, edges with eight equivalent U(1)Al6Sn6 cuboctahedra, edges with eight equivalent Al(1)U4Al2Sn6 cuboctahedra, edges with eight equivalent Sn(3)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(1)U4Al4Sn4 cuboctahedra, faces with four equivalent U(1)Al6Sn6 cuboctahedra, faces with four equivalent Al(1)U4Al2Sn6 cuboctahedra, faces with four equivalent Al(2)U4Al4Sn4 cuboctahedra, and faces with four equivalent Sn(2)U4Al8 cuboctahedra. There are three inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to four equivalent U(1), four equivalent Al(1), and four equivalent Sn(3) atoms to form distorted SnU4Al4Sn4 cuboctahedra that share corners with four equivalent Sn(1)U4Al4Sn4 cuboctahedra, corners with eight equivalent Al(2)U4Al4Sn4 cuboctahedra, edges with eight equivalent U(1)Al6Sn6 cuboctahedra, edges with eight equivalent Al(1)U4Al2Sn6 cuboctahedra, edges with eight equivalent Sn(2)U4Al8 cuboctahedra, faces with two equivalent Al(2)U4Al4Sn4 cuboctahedra, faces with four equivalent U(1)Al6Sn6 cuboctahedra, faces with four equivalent Al(1)U4Al2Sn6 cuboctahedra, faces with four equivalent Sn(1)U4Al4Sn4 cuboctahedra, and faces with four equivalent Sn(3)U4Al4Sn4 cuboctahedra. In the second Sn site, Sn(2) is bonded to four equivalent U(1), four equivalent Al(1), and four equivalent Al(2) atoms to form SnU4Al8 cuboctahedra that share corners with four equivalent Sn(2)U4Al8 cuboctahedra, corners with eight equivalent Sn(3)U4Al4Sn4 cuboctahedra, edges with eight equivalent U(1)Al6Sn6 cuboctahedra, edges with eight equivalent Al(1)U4Al2Sn6 cuboctahedra, edges with eight equivalent Sn(1)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(3)U4Al4Sn4 cuboctahedra, faces with four equivalent U(1)Al6Sn6 cuboctahedra, faces with four equivalent Al(1)U4Al2Sn6 cuboctahedra, faces with four equivalent Al(2)U4Al4Sn4 cuboctahedra, and faces with four equivalent Sn(2)U4Al8 cuboctahedra. In the third Sn site, Sn(3) is bonded to four equivalent U(1), four equivalent Al(1), and four equivalent Sn(1) atoms to form distorted SnU4Al4Sn4 cuboctahedra that share corners with four equivalent Sn(3)U4Al4Sn4 cuboctahedra, corners with eight equivalent Sn(2)U4Al8 cuboctahedra, edges with eight equivalent U(1)Al6Sn6 cuboctahedra, edges with eight equivalent Al(1)U4Al2Sn6 cuboctahedra, edges with eight equivalent Al(2)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(2)U4Al8 cuboctahedra, faces with four equivalent U(1)Al6Sn6 cuboctahedra, faces with four equivalent Al(1)U4Al2Sn6 cuboctahedra, faces with four equivalent Sn(1)U4Al4Sn4 cuboctahedra, and faces with four equivalent Sn(3)U4Al4Sn4 cuboctahedra.
U2(AlSn)3 crystallizes in the orthorhombic Pmmm space group. U(1) is bonded to two equivalent Al(2), four equivalent Al(1), two equivalent Sn(1), two equivalent Sn(2), and two equivalent Sn(3) atoms to form UAl6Sn6 cuboctahedra that share corners with twelve equivalent U(1)Al6Sn6 cuboctahedra, edges with four equivalent Al(2)U4Al4Sn4 cuboctahedra, edges with four equivalent Sn(1)U4Al4Sn4 cuboctahedra, edges with four equivalent Sn(3)U4Al4Sn4 cuboctahedra, edges with four equivalent Sn(2)U4Al8 cuboctahedra, edges with eight equivalent Al(1)U4Al2Sn6 cuboctahedra, faces with two equivalent Al(2)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(1)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(3)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(2)U4Al8 cuboctahedra, faces with four equivalent Al(1)U4Al2Sn6 cuboctahedra, and faces with six equivalent U(1)Al6Sn6 cuboctahedra. Both U(1)-Al(2) bond lengths are 3.14 Å. All U(1)-Al(1) bond lengths are 3.15 Å. Both U(1)-Sn(1) bond lengths are 3.17 Å. Both U(1)-Sn(2) bond lengths are 3.15 Å. Both U(1)-Sn(3) bond lengths are 3.18 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent U(1), two equivalent Al(2), two equivalent Sn(1), two equivalent Sn(2), and two equivalent Sn(3) atoms to form distorted AlU4Al2Sn6 cuboctahedra that share corners with twelve equivalent Al(1)U4Al2Sn6 cuboctahedra, edges with four equivalent Al(2)U4Al4Sn4 cuboctahedra, edges with four equivalent Sn(1)U4Al4Sn4 cuboctahedra, edges with four equivalent Sn(3)U4Al4Sn4 cuboctahedra, edges with four equivalent Sn(2)U4Al8 cuboctahedra, edges with eight equivalent U(1)Al6Sn6 cuboctahedra, faces with two equivalent Al(2)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(1)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(3)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(2)U4Al8 cuboctahedra, faces with four equivalent U(1)Al6Sn6 cuboctahedra, and faces with six equivalent Al(1)U4Al2Sn6 cuboctahedra. Both Al(1)-Al(2) bond lengths are 3.07 Å. Both Al(1)-Sn(1) bond lengths are 3.27 Å. Both Al(1)-Sn(2) bond lengths are 3.05 Å. Both Al(1)-Sn(3) bond lengths are 3.25 Å. In the second Al site, Al(2) is bonded to four equivalent U(1), four equivalent Al(1), and four equivalent Sn(2) atoms to form distorted AlU4Al4Sn4 cuboctahedra that share corners with four equivalent Al(2)U4Al4Sn4 cuboctahedra, corners with eight equivalent Sn(1)U4Al4Sn4 cuboctahedra, edges with eight equivalent U(1)Al6Sn6 cuboctahedra, edges with eight equivalent Al(1)U4Al2Sn6 cuboctahedra, edges with eight equivalent Sn(3)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(1)U4Al4Sn4 cuboctahedra, faces with four equivalent U(1)Al6Sn6 cuboctahedra, faces with four equivalent Al(1)U4Al2Sn6 cuboctahedra, faces with four equivalent Al(2)U4Al4Sn4 cuboctahedra, and faces with four equivalent Sn(2)U4Al8 cuboctahedra. All Al(2)-Sn(2) bond lengths are 3.15 Å. There are three inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to four equivalent U(1), four equivalent Al(1), and four equivalent Sn(3) atoms to form distorted SnU4Al4Sn4 cuboctahedra that share corners with four equivalent Sn(1)U4Al4Sn4 cuboctahedra, corners with eight equivalent Al(2)U4Al4Sn4 cuboctahedra, edges with eight equivalent U(1)Al6Sn6 cuboctahedra, edges with eight equivalent Al(1)U4Al2Sn6 cuboctahedra, edges with eight equivalent Sn(2)U4Al8 cuboctahedra, faces with two equivalent Al(2)U4Al4Sn4 cuboctahedra, faces with four equivalent U(1)Al6Sn6 cuboctahedra, faces with four equivalent Al(1)U4Al2Sn6 cuboctahedra, faces with four equivalent Sn(1)U4Al4Sn4 cuboctahedra, and faces with four equivalent Sn(3)U4Al4Sn4 cuboctahedra. All Sn(1)-Sn(3) bond lengths are 3.15 Å. In the second Sn site, Sn(2) is bonded to four equivalent U(1), four equivalent Al(1), and four equivalent Al(2) atoms to form SnU4Al8 cuboctahedra that share corners with four equivalent Sn(2)U4Al8 cuboctahedra, corners with eight equivalent Sn(3)U4Al4Sn4 cuboctahedra, edges with eight equivalent U(1)Al6Sn6 cuboctahedra, edges with eight equivalent Al(1)U4Al2Sn6 cuboctahedra, edges with eight equivalent Sn(1)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(3)U4Al4Sn4 cuboctahedra, faces with four equivalent U(1)Al6Sn6 cuboctahedra, faces with four equivalent Al(1)U4Al2Sn6 cuboctahedra, faces with four equivalent Al(2)U4Al4Sn4 cuboctahedra, and faces with four equivalent Sn(2)U4Al8 cuboctahedra. In the third Sn site, Sn(3) is bonded to four equivalent U(1), four equivalent Al(1), and four equivalent Sn(1) atoms to form distorted SnU4Al4Sn4 cuboctahedra that share corners with four equivalent Sn(3)U4Al4Sn4 cuboctahedra, corners with eight equivalent Sn(2)U4Al8 cuboctahedra, edges with eight equivalent U(1)Al6Sn6 cuboctahedra, edges with eight equivalent Al(1)U4Al2Sn6 cuboctahedra, edges with eight equivalent Al(2)U4Al4Sn4 cuboctahedra, faces with two equivalent Sn(2)U4Al8 cuboctahedra, faces with four equivalent U(1)Al6Sn6 cuboctahedra, faces with four equivalent Al(1)U4Al2Sn6 cuboctahedra, faces with four equivalent Sn(1)U4Al4Sn4 cuboctahedra, and faces with four equivalent Sn(3)U4Al4Sn4 cuboctahedra.