U2(NiCu)5 crystallizes in the monoclinic Cm space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 16-coordinate geometry to one Ni(3), one Ni(4), two equivalent Ni(2), three equivalent Ni(1), three equivalent Ni(5), two equivalent Cu(2), and four equivalent Cu(1) atoms. In the second U site, U(2) is bonded in a 16-coordinate geometry to one Ni(2), one Ni(5), two equivalent Ni(3), three equivalent Ni(4), two equivalent Cu(1), three equivalent Cu(3), and four equivalent Cu(2) atoms. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent U(1), one Ni(2), one Ni(3), three equivalent Ni(5), two equivalent Cu(1), and two equivalent Cu(2) atoms to form distorted NiU3Cu4Ni5 cuboctahedra that share corners with two equivalent Ni(2)U3Cu5Ni4 cuboctahedra, corners with two equivalent Ni(3)U3Cu5Ni4 cuboctahedra, corners with four equivalent Cu(1)U3Cu3Ni6 cuboctahedra, corners with four equivalent Cu(2)U3Cu3Ni6 cuboctahedra, corners with six equivalent Cu(3)U3Cu4Ni5 cuboctahedra, edges with six equivalent Ni(1)U3Cu4Ni5 cuboctahedra, faces with three equivalent Ni(2)U3Cu5Ni4 cuboctahedra, faces with three equivalent Ni(3)U3Cu5Ni4 cuboctahedra, faces with six equivalent Cu(1)U3Cu3Ni6 cuboctahedra, and faces with six equivalent Cu(2)U3Cu3Ni6 cuboctahedra. In the second Ni site, Ni(2) is bonded to one U(2), two equivalent U(1), one Ni(1), one Ni(5), two equivalent Ni(4), one Cu(3), and four equivalent Cu(1) atoms to form distorted NiU3Cu5Ni4 cuboctahedra that share corners with two equivalent Ni(1)U3Cu4Ni5 cuboctahedra, corners with two equivalent Ni(3)U3Cu5Ni4 cuboctahedra, corners with two equivalent Cu(3)U3Cu4Ni5 cuboctahedra, corners with four equivalent Ni(2)U3Cu5Ni4 cuboctahedra, corners with eight equivalent Cu(2)U3Cu3Ni6 cuboctahedra, edges with two equivalent Ni(2)U3Cu5Ni4 cuboctahedra, edges with four equivalent Ni(3)U3Cu5Ni4 cuboctahedra, faces with three equivalent Ni(1)U3Cu4Ni5 cuboctahedra, faces with three equivalent Cu(3)U3Cu4Ni5 cuboctahedra, faces with four equivalent Cu(2)U3Cu3Ni6 cuboctahedra, and faces with eight equivalent Cu(1)U3Cu3Ni6 cuboctahedra. In the third Ni site, Ni(3) is bonded to one U(1), two equivalent U(2), one Ni(1), one Ni(4), two equivalent Ni(5), one Cu(3), and four equivalent Cu(2) atoms to form distorted NiU3Cu5Ni4 cuboctahedra that share corners with two equivalent Ni(1)U3Cu4Ni5 cuboctahedra, corners with two equivalent Ni(2)U3Cu5Ni4 cuboctahedra, corners with two equivalent Cu(3)U3Cu4Ni5 cuboctahedra, corners with four equivalent Ni(3)U3Cu5Ni4 cuboctahedra, corners with eight equivalent Cu(1)U3Cu3Ni6 cuboctahedra, edges with two equivalent Ni(3)U3Cu5Ni4 cuboctahedra, edges with four equivalent Ni(2)U3Cu5Ni4 cuboctahedra, faces with three equivalent Ni(1)U3Cu4Ni5 cuboctahedra, faces with three equivalent Cu(3)U3Cu4Ni5 cuboctahedra, faces with four equivalent Cu(1)U3Cu3Ni6 cuboctahedra, and faces with eight equivalent Cu(2)U3Cu3Ni6 cuboctahedra. In the fourth Ni site, Ni(4) is bonded in a 16-coordinate geometry to one U(1), three equivalent U(2), one Ni(3), two equivalent Ni(2), two equivalent Cu(2), three equivalent Cu(3), and four equivalent Cu(1) atoms. In the fifth Ni site, Ni(5) is bonded in a 16-coordinate geometry to one U(2), three equivalent U(1), one Ni(2), two equivalent Ni(3), three equivalent Ni(1), two equivalent Cu(1), and four equivalent Cu(2) atoms. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one U(2), two equivalent U(1), one Ni(1), one Ni(5), two equivalent Ni(2), two equivalent Ni(4), one Cu(3), and two equivalent Cu(1) atoms to form distorted CuU3Cu3Ni6 cuboctahedra that share corners with two equivalent Ni(1)U3Cu4Ni5 cuboctahedra, corners with two equivalent Cu(3)U3Cu4Ni5 cuboctahedra, corners with four equivalent Ni(3)U3Cu5Ni4 cuboctahedra, corners with four equivalent Cu(1)U3Cu3Ni6 cuboctahedra, corners with six equivalent Cu(2)U3Cu3Ni6 cuboctahedra, edges with two equivalent Cu(1)U3Cu3Ni6 cuboctahedra, edges with four equivalent Cu(2)U3Cu3Ni6 cuboctahedra, faces with two equivalent Ni(3)U3Cu5Ni4 cuboctahedra, faces with two equivalent Cu(2)U3Cu3Ni6 cuboctahedra, faces with three equivalent Ni(1)U3Cu4Ni5 cuboctahedra, faces with three equivalent Cu(3)U3Cu4Ni5 cuboctahedra, faces with four equivalent Ni(2)U3Cu5Ni4 cuboctahedra, and faces with four equivalent Cu(1)U3Cu3Ni6 cuboctahedra. In the second Cu site, Cu(2) is bonded to one U(1), two equivalent U(2), one Ni(1), one Ni(4), two equivalent Ni(3), two equivalent Ni(5), one Cu(3), and two equivalent Cu(2) atoms to form distorted CuU3Cu3Ni6 cuboctahedra that share corners with two equivalent Ni(1)U3Cu4Ni5 cuboctahedra, corners with two equivalent Cu(3)U3Cu4Ni5 cuboctahedra, corners with four equivalent Ni(2)U3Cu5Ni4 cuboctahedra, corners with four equivalent Cu(2)U3Cu3Ni6 cuboctahedra, corners with six equivalent Cu(1)U3Cu3Ni6 cuboctahedra, edges with two equivalent Cu(2)U3Cu3Ni6 cuboctahedra, edges with four equivalent Cu(1)U3Cu3Ni6 cuboctahedra, faces with two equivalent Ni(2)U3Cu5Ni4 cuboctahedra, faces with two equivalent Cu(1)U3Cu3Ni6 cuboctahedra, faces with three equivalent Ni(1)U3Cu4Ni5 cuboctahedra, faces with three equivalent Cu(3)U3Cu4Ni5 cuboctahedra, faces with four equivalent Ni(3)U3Cu5Ni4 cuboctahedra, and faces with four equivalent Cu(2)U3Cu3Ni6 cuboctahedra. In the third Cu site, Cu(3) is bonded to three equivalent U(2), one Ni(2), one Ni(3), three equivalent Ni(4), two equivalent Cu(1), and two equivalent Cu(2) atoms to form CuU3Cu4Ni5 cuboctahedra that share corners with two equivalent Ni(2)U3Cu5Ni4 cuboctahedra, corners with two equivalent Ni(3)U3Cu5Ni4 cuboctahedra, corners with four equivalent Cu(1)U3Cu3Ni6 cuboctahedra, corners with four equivalent Cu(2)U3Cu3Ni6 cuboctahedra, corners with six equivalent Ni(1)U3Cu4Ni5 cuboctahedra, edges with six equivalent Cu(3)U3Cu4Ni5 cuboctahedra, faces with three equivalent Ni(2)U3Cu5Ni4 cuboctahedra, faces with three equivalent Ni(3)U3Cu5Ni4 cuboctahedra, faces with six equivalent Cu(1)U3Cu3Ni6 cuboctahedra, and faces with six equivalent Cu(2)U3Cu3Ni6 cuboctahedra.
U2(NiCu)5 crystallizes in the monoclinic Cm space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 16-coordinate geometry to one Ni(3), one Ni(4), two equivalent Ni(2), three equivalent Ni(1), three equivalent Ni(5), two equivalent Cu(2), and four equivalent Cu(1) atoms. The U(1)-Ni(3) bond length is 2.79 Å. The U(1)-Ni(4) bond length is 2.98 Å. Both U(1)-Ni(2) bond lengths are 2.82 Å. There is one shorter (2.80 Å) and two longer (2.83 Å) U(1)-Ni(1) bond lengths. There are two shorter (2.92 Å) and one longer (3.02 Å) U(1)-Ni(5) bond length. Both U(1)-Cu(2) bond lengths are 2.83 Å. There are two shorter (2.83 Å) and two longer (2.86 Å) U(1)-Cu(1) bond lengths. In the second U site, U(2) is bonded in a 16-coordinate geometry to one Ni(2), one Ni(5), two equivalent Ni(3), three equivalent Ni(4), two equivalent Cu(1), three equivalent Cu(3), and four equivalent Cu(2) atoms. The U(2)-Ni(2) bond length is 2.80 Å. The U(2)-Ni(5) bond length is 2.94 Å. Both U(2)-Ni(3) bond lengths are 2.80 Å. There are two shorter (2.92 Å) and one longer (3.02 Å) U(2)-Ni(4) bond length. Both U(2)-Cu(1) bond lengths are 2.85 Å. There is one shorter (2.81 Å) and two longer (2.84 Å) U(2)-Cu(3) bond lengths. There are two shorter (2.83 Å) and two longer (2.85 Å) U(2)-Cu(2) bond lengths. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent U(1), one Ni(2), one Ni(3), three equivalent Ni(5), two equivalent Cu(1), and two equivalent Cu(2) atoms to form distorted NiU3Cu4Ni5 cuboctahedra that share corners with two equivalent Ni(2)U3Cu5Ni4 cuboctahedra, corners with two equivalent Ni(3)U3Cu5Ni4 cuboctahedra, corners with four equivalent Cu(1)U3Cu3Ni6 cuboctahedra, corners with four equivalent Cu(2)U3Cu3Ni6 cuboctahedra, corners with six equivalent Cu(3)U3Cu4Ni5 cuboctahedra, edges with six equivalent Ni(1)U3Cu4Ni5 cuboctahedra, faces with three equivalent Ni(2)U3Cu5Ni4 cuboctahedra, faces with three equivalent Ni(3)U3Cu5Ni4 cuboctahedra, faces with six equivalent Cu(1)U3Cu3Ni6 cuboctahedra, and faces with six equivalent Cu(2)U3Cu3Ni6 cuboctahedra. The Ni(1)-Ni(2) bond length is 2.44 Å. The Ni(1)-Ni(3) bond length is 2.44 Å. There are two shorter (2.81 Å) and one longer (2.85 Å) Ni(1)-Ni(5) bond length. Both Ni(1)-Cu(1) bond lengths are 2.41 Å. Both Ni(1)-Cu(2) bond lengths are 2.39 Å. In the second Ni site, Ni(2) is bonded to one U(2), two equivalent U(1), one Ni(1), one Ni(5), two equivalent Ni(4), one Cu(3), and four equivalent Cu(1) atoms to form distorted NiU3Cu5Ni4 cuboctahedra that share corners with two equivalent Ni(1)U3Cu4Ni5 cuboctahedra, corners with two equivalent Ni(3)U3Cu5Ni4 cuboctahedra, corners with two equivalent Cu(3)U3Cu4Ni5 cuboctahedra, corners with four equivalent Ni(2)U3Cu5Ni4 cuboctahedra, corners with eight equivalent Cu(2)U3Cu3Ni6 cuboctahedra, edges with two equivalent Ni(2)U3Cu5Ni4 cuboctahedra, edges with four equivalent Ni(3)U3Cu5Ni4 cuboctahedra, faces with three equivalent Ni(1)U3Cu4Ni5 cuboctahedra, faces with three equivalent Cu(3)U3Cu4Ni5 cuboctahedra, faces with four equivalent Cu(2)U3Cu3Ni6 cuboctahedra, and faces with eight equivalent Cu(1)U3Cu3Ni6 cuboctahedra. The Ni(2)-Ni(5) bond length is 2.84 Å. Both Ni(2)-Ni(4) bond lengths are 2.81 Å. The Ni(2)-Cu(3) bond length is 2.42 Å. There are two shorter (2.41 Å) and two longer (2.43 Å) Ni(2)-Cu(1) bond lengths. In the third Ni site, Ni(3) is bonded to one U(1), two equivalent U(2), one Ni(1), one Ni(4), two equivalent Ni(5), one Cu(3), and four equivalent Cu(2) atoms to form distorted NiU3Cu5Ni4 cuboctahedra that share corners with two equivalent Ni(1)U3Cu4Ni5 cuboctahedra, corners with two equivalent Ni(2)U3Cu5Ni4 cuboctahedra, corners with two equivalent Cu(3)U3Cu4Ni5 cuboctahedra, corners with four equivalent Ni(3)U3Cu5Ni4 cuboctahedra, corners with eight equivalent Cu(1)U3Cu3Ni6 cuboctahedra, edges with two equivalent Ni(3)U3Cu5Ni4 cuboctahedra, edges with four equivalent Ni(2)U3Cu5Ni4 cuboctahedra, faces with three equivalent Ni(1)U3Cu4Ni5 cuboctahedra, faces with three equivalent Cu(3)U3Cu4Ni5 cuboctahedra, faces with four equivalent Cu(1)U3Cu3Ni6 cuboctahedra, and faces with eight equivalent Cu(2)U3Cu3Ni6 cuboctahedra. The Ni(3)-Ni(4) bond length is 2.81 Å. Both Ni(3)-Ni(5) bond lengths are 2.80 Å. The Ni(3)-Cu(3) bond length is 2.45 Å. There are two shorter (2.40 Å) and two longer (2.44 Å) Ni(3)-Cu(2) bond lengths. In the fourth Ni site, Ni(4) is bonded in a 16-coordinate geometry to one U(1), three equivalent U(2), one Ni(3), two equivalent Ni(2), two equivalent Cu(2), three equivalent Cu(3), and four equivalent Cu(1) atoms. Both Ni(4)-Cu(2) bond lengths are 2.83 Å. There are two shorter (2.81 Å) and one longer (2.85 Å) Ni(4)-Cu(3) bond length. There are two shorter (2.81 Å) and two longer (2.86 Å) Ni(4)-Cu(1) bond lengths. In the fifth Ni site, Ni(5) is bonded in a 16-coordinate geometry to one U(2), three equivalent U(1), one Ni(2), two equivalent Ni(3), three equivalent Ni(1), two equivalent Cu(1), and four equivalent Cu(2) atoms. Both Ni(5)-Cu(1) bond lengths are 2.84 Å. There are two shorter (2.80 Å) and two longer (2.85 Å) Ni(5)-Cu(2) bond lengths. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one U(2), two equivalent U(1), one Ni(1), one Ni(5), two equivalent Ni(2), two equivalent Ni(4), one Cu(3), and two equivalent Cu(1) atoms to form distorted CuU3Cu3Ni6 cuboctahedra that share corners with two equivalent Ni(1)U3Cu4Ni5 cuboctahedra, corners with two equivalent Cu(3)U3Cu4Ni5 cuboctahedra, corners with four equivalent Ni(3)U3Cu5Ni4 cuboctahedra, corners with four equivalent Cu(1)U3Cu3Ni6 cuboctahedra, corners with six equivalent Cu(2)U3Cu3Ni6 cuboctahedra, edges with two equivalent Cu(1)U3Cu3Ni6 cuboctahedra, edges with four equivalent Cu(2)U3Cu3Ni6 cuboctahedra, faces with two equivalent Ni(3)U3Cu5Ni4 cuboctahedra, faces with two equivalent Cu(2)U3Cu3Ni6 cuboctahedra, faces with three equivalent Ni(1)U3Cu4Ni5 cuboctahedra, faces with three equivalent Cu(3)U3Cu4Ni5 cuboctahedra, faces with four equivalent Ni(2)U3Cu5Ni4 cuboctahedra, and faces with four equivalent Cu(1)U3Cu3Ni6 cuboctahedra. The Cu(1)-Cu(3) bond length is 2.38 Å. There is one shorter (2.37 Å) and one longer (2.40 Å) Cu(1)-Cu(1) bond length. In the second Cu site, Cu(2) is bonded to one U(1), two equivalent U(2), one Ni(1), one Ni(4), two equivalent Ni(3), two equivalent Ni(5), one Cu(3), and two equivalent Cu(2) atoms to form distorted CuU3Cu3Ni6 cuboctahedra that share corners with two equivalent Ni(1)U3Cu4Ni5 cuboctahedra, corners with two equivalent Cu(3)U3Cu4Ni5 cuboctahedra, corners with four equivalent Ni(2)U3Cu5Ni4 cuboctahedra, corners with four equivalent Cu(2)U3Cu3Ni6 cuboctahedra, corners with six equivalent Cu(1)U3Cu3Ni6 cuboctahedra, edges with two equivalent Cu(2)U3Cu3Ni6 cuboctahedra, edges with four equivalent Cu(1)U3Cu3Ni6 cuboctahedra, faces with two equivalent Ni(2)U3Cu5Ni4 cuboctahedra, faces with two equivalent Cu(1)U3Cu3Ni6 cuboctahedra, faces with three equivalent Ni(1)U3Cu4Ni5 cuboctahedra, faces with three equivalent Cu(3)U3Cu4Ni5 cuboctahedra, faces with four equivalent Ni(3)U3Cu5Ni4 cuboctahedra, and faces with four equivalent Cu(2)U3Cu3Ni6 cuboctahedra. The Cu(2)-Cu(3) bond length is 2.43 Å. There is one shorter (2.36 Å) and one longer (2.41 Å) Cu(2)-Cu(2) bond length. In the third Cu site, Cu(3) is bonded to three equivalent U(2), one Ni(2), one Ni(3), three equivalent Ni(4), two equivalent Cu(1), and two equivalent Cu(2) atoms to form CuU3Cu4Ni5 cuboctahedra that share corners with two equivalent Ni(2)U3Cu5Ni4 cuboctahedra, corners with two equivalent Ni(3)U3Cu5Ni4 cuboctahedra, corners with four equivalent Cu(1)U3Cu3Ni6 cuboctahedra, corners with four equivalent Cu(2)U3Cu3Ni6 cuboctahedra, corners with six equivalent Ni(1)U3Cu4Ni5 cuboctahedra, edges with six equivalent Cu(3)U3Cu4Ni5 cuboctahedra, faces with three equivalent Ni(2)U3Cu5Ni4 cuboctahedra, faces with three equivalent Ni(3)U3Cu5Ni4 cuboctahedra, faces with six equivalent Cu(1)U3Cu3Ni6 cuboctahedra, and faces with six equivalent Cu(2)U3Cu3Ni6 cuboctahedra.