UCoAl is alpha-derived structured and crystallizes in the orthorhombic Amm2 space group. There are seven inequivalent U sites. In the first U site, U(1) is bonded in a 16-coordinate geometry to one U(1); three U(2,2); one Co(3); two equivalent Co(1); two equivalent Co(2); three equivalent Al(1); and four equivalent Al(2) atoms. In the second U site, U(2) is bonded in a 16-coordinate geometry to one U(2); three U(1,1); one Co(1); two equivalent Co(3); four equivalent Co(2); two equivalent Al(2); and three equivalent Al(1) atoms. In the third U site, U(2) is bonded in a 16-coordinate geometry to one U(2), three equivalent U(1), one Co(1), two equivalent Co(3), four equivalent Co(2), two equivalent Al(2), and three equivalent Al(1) atoms. In the fourth U site, U(1) is bonded in a 16-coordinate geometry to one U(1); three U(2,2); one Co(3); two equivalent Co(1); two equivalent Co(2); three equivalent Al(1); and four equivalent Al(2) atoms. In the fifth U site, U(1) is bonded in a 16-coordinate geometry to one U(1); three U(2,2); one Co(3); two equivalent Co(1); two equivalent Co(2); three equivalent Al(1); and four equivalent Al(2) atoms. In the sixth U site, U(2) is bonded in a 16-coordinate geometry to one U(2); three U(1,1); one Co(1); two equivalent Co(3); four equivalent Co(2); two equivalent Al(2); and three equivalent Al(1) atoms. In the seventh U site, U(2) is bonded in a 16-coordinate geometry to one U(2), three equivalent U(1), one Co(1), two equivalent Co(3), four equivalent Co(2), two equivalent Al(2), and three equivalent Al(1) atoms. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded to two U(2,2); four U(1,1); two equivalent Al(1); and four equivalent Al(2) atoms to form CoU6Al6 cuboctahedra that share corners with four equivalent Co(1)U6Al6 cuboctahedra, edges with two equivalent Co(1)U6Al6 cuboctahedra, and faces with eight equivalent Al(2)U6Al4Co2 cuboctahedra. In the second Co site, Co(2) is bonded in a 12-coordinate geometry to two U(1,1); four U(2,2,2,2); two equivalent Co(2); two equivalent Co(3); and two equivalent Al(1) atoms. In the third Co site, Co(3) is bonded in a 12-coordinate geometry to two U(1,1); four U(2,2); four equivalent Co(2); and two equivalent Al(1) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 12-coordinate geometry to three U(1,1); three U(2,2); one Co(1); one Co(3); two equivalent Co(2); and two equivalent Al(2) atoms. In the second Al site, Al(2) is bonded to two U(2,2); four U(1,1,1); two equivalent Co(1); two equivalent Al(1); and two equivalent Al(2) atoms to form distorted AlU6Al4Co2 cuboctahedra that share corners with four equivalent Al(2)U6Al4Co2 cuboctahedra, edges with two equivalent Al(2)U6Al4Co2 cuboctahedra, faces with four equivalent Co(1)U6Al6 cuboctahedra, and faces with four equivalent Al(2)U6Al4Co2 cuboctahedra.
UCoAl is alpha-derived structured and crystallizes in the orthorhombic Amm2 space group. There are seven inequivalent U sites. In the first U site, U(1) is bonded in a 16-coordinate geometry to one U(1); three U(2,2); one Co(3); two equivalent Co(1); two equivalent Co(2); three equivalent Al(1); and four equivalent Al(2) atoms. The U(1)-U(1) bond length is 3.13 Å. There are two shorter (3.21 Å) and one longer (3.38 Å) U(1)-U(2,2) bond length. The U(1)-Co(3) bond length is 2.83 Å. Both U(1)-Co(1) bond lengths are 3.08 Å. Both U(1)-Co(2) bond lengths are 2.83 Å. There are two shorter (3.12 Å) and one longer (3.13 Å) U(1)-Al(1) bond length. There are two shorter (3.07 Å) and two longer (3.11 Å) U(1)-Al(2) bond lengths. In the second U site, U(2) is bonded in a 16-coordinate geometry to one U(2); three U(1,1); one Co(1); two equivalent Co(3); four equivalent Co(2); two equivalent Al(2); and three equivalent Al(1) atoms. The U(2)-U(2) bond length is 2.63 Å. The U(2)-U(1) bond length is 3.38 Å. The U(2)-Co(1) bond length is 3.03 Å. Both U(2)-Co(3) bond lengths are 2.96 Å. There are two shorter (2.93 Å) and two longer (3.02 Å) U(2)-Co(2) bond lengths. Both U(2)-Al(2) bond lengths are 3.08 Å. There is one shorter (3.04 Å) and two longer (3.17 Å) U(2)-Al(1) bond lengths. In the third U site, U(2) is bonded in a 16-coordinate geometry to one U(2), three equivalent U(1), one Co(1), two equivalent Co(3), four equivalent Co(2), two equivalent Al(2), and three equivalent Al(1) atoms. There are two shorter (3.21 Å) and one longer (3.38 Å) U(2)-U(1) bond length. The U(2)-Co(1) bond length is 3.03 Å. Both U(2)-Co(3) bond lengths are 2.96 Å. There are two shorter (2.93 Å) and two longer (3.02 Å) U(2)-Co(2) bond lengths. Both U(2)-Al(2) bond lengths are 3.08 Å. There is one shorter (3.04 Å) and two longer (3.17 Å) U(2)-Al(1) bond lengths. In the fourth U site, U(1) is bonded in a 16-coordinate geometry to one U(1); three U(2,2); one Co(3); two equivalent Co(1); two equivalent Co(2); three equivalent Al(1); and four equivalent Al(2) atoms. The U(1)-U(2) bond length is 3.38 Å. The U(1)-Co(3) bond length is 2.83 Å. Both U(1)-Co(1) bond lengths are 3.08 Å. Both U(1)-Co(2) bond lengths are 2.83 Å. There are two shorter (3.12 Å) and one longer (3.13 Å) U(1)-Al(1) bond length. There are two shorter (3.07 Å) and two longer (3.11 Å) U(1)-Al(2) bond lengths. In the fifth U site, U(1) is bonded in a 16-coordinate geometry to one U(1); three U(2,2); one Co(3); two equivalent Co(1); two equivalent Co(2); three equivalent Al(1); and four equivalent Al(2) atoms. The U(1)-U(1) bond length is 3.13 Å. Both U(1)-U(2) bond lengths are 3.21 Å. The U(1)-Co(3) bond length is 2.83 Å. Both U(1)-Co(1) bond lengths are 3.08 Å. Both U(1)-Co(2) bond lengths are 2.83 Å. There are two shorter (3.12 Å) and one longer (3.13 Å) U(1)-Al(1) bond length. There are two shorter (3.07 Å) and two longer (3.11 Å) U(1)-Al(2) bond lengths. In the sixth U site, U(2) is bonded in a 16-coordinate geometry to one U(2); three U(1,1); one Co(1); two equivalent Co(3); four equivalent Co(2); two equivalent Al(2); and three equivalent Al(1) atoms. The U(2)-U(2) bond length is 2.63 Å. The U(2)-Co(1) bond length is 3.03 Å. Both U(2)-Co(3) bond lengths are 2.96 Å. There are two shorter (2.93 Å) and two longer (3.02 Å) U(2)-Co(2) bond lengths. Both U(2)-Al(2) bond lengths are 3.08 Å. There is one shorter (3.04 Å) and two longer (3.17 Å) U(2)-Al(1) bond lengths. In the seventh U site, U(2) is bonded in a 16-coordinate geometry to one U(2), three equivalent U(1), one Co(1), two equivalent Co(3), four equivalent Co(2), two equivalent Al(2), and three equivalent Al(1) atoms. The U(2)-Co(1) bond length is 3.03 Å. Both U(2)-Co(3) bond lengths are 2.96 Å. There are two shorter (2.93 Å) and two longer (3.02 Å) U(2)-Co(2) bond lengths. Both U(2)-Al(2) bond lengths are 3.08 Å. There is one shorter (3.04 Å) and two longer (3.17 Å) U(2)-Al(1) bond lengths. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded to two U(2,2); four U(1,1); two equivalent Al(1); and four equivalent Al(2) atoms to form CoU6Al6 cuboctahedra that share corners with four equivalent Co(1)U6Al6 cuboctahedra, edges with two equivalent Co(1)U6Al6 cuboctahedra, and faces with eight equivalent Al(2)U6Al4Co2 cuboctahedra. Both Co(1)-Al(1) bond lengths are 2.63 Å. There are two shorter (2.61 Å) and two longer (2.73 Å) Co(1)-Al(2) bond lengths. In the second Co site, Co(2) is bonded in a 12-coordinate geometry to two U(1,1); four U(2,2,2,2); two equivalent Co(2); two equivalent Co(3); and two equivalent Al(1) atoms. There is one shorter (2.51 Å) and one longer (2.80 Å) Co(2)-Co(2) bond length. There is one shorter (2.57 Å) and one longer (2.76 Å) Co(2)-Co(3) bond length. Both Co(2)-Al(1) bond lengths are 2.46 Å. In the third Co site, Co(3) is bonded in a 12-coordinate geometry to two U(1,1); four U(2,2); four equivalent Co(2); and two equivalent Al(1) atoms. Both Co(3)-Al(1) bond lengths are 2.47 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 12-coordinate geometry to three U(1,1); three U(2,2); one Co(1); one Co(3); two equivalent Co(2); and two equivalent Al(2) atoms. Both Al(1)-Al(2) bond lengths are 2.64 Å. In the second Al site, Al(2) is bonded to two U(2,2); four U(1,1,1); two equivalent Co(1); two equivalent Al(1); and two equivalent Al(2) atoms to form distorted AlU6Al4Co2 cuboctahedra that share corners with four equivalent Al(2)U6Al4Co2 cuboctahedra, edges with two equivalent Al(2)U6Al4Co2 cuboctahedra, faces with four equivalent Co(1)U6Al6 cuboctahedra, and faces with four equivalent Al(2)U6Al4Co2 cuboctahedra. There is one shorter (2.59 Å) and one longer (2.71 Å) Al(2)-Al(2) bond length.