Lu5(Co2Si7)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Lu sites. In the first Lu site, Lu(1) is bonded to two equivalent Co(2), one Si(1), one Si(6), two equivalent Si(4), three equivalent Si(2), and three equivalent Si(7) atoms to form a mixture of distorted corner, face, and edge-sharing LuCo2Si10 cuboctahedra. In the second Lu site, Lu(2) is bonded to two equivalent Co(2), one Si(1), one Si(6), two equivalent Si(5), three equivalent Si(2), and three equivalent Si(7) atoms to form a mixture of distorted corner, face, and edge-sharing LuCo2Si10 cuboctahedra. In the third Lu site, Lu(3) is bonded in a 18-coordinate geometry to two equivalent Co(2), four equivalent Co(1), two equivalent Si(1), two equivalent Si(4), two equivalent Si(5), two equivalent Si(6), and four equivalent Si(3) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 10-coordinate geometry to two equivalent Lu(3), one Co(1), one Si(1), one Si(4), one Si(5), one Si(6), and three equivalent Si(3) atoms. In the second Co site, Co(2) is bonded in a 10-coordinate geometry to one Lu(3), two equivalent Lu(1), two equivalent Lu(2), one Si(1), one Si(2), one Si(4), one Si(5), and one Si(6) atom. There are seven inequivalent Si sites. In the first Si site, Si(6) is bonded in a 8-coordinate geometry to one Lu(1), one Lu(2), one Lu(3), one Co(1), one Co(2), one Si(3), one Si(4), and one Si(5) atom. In the second Si site, Si(7) is bonded in a 8-coordinate geometry to three equivalent Lu(1), three equivalent Lu(2), one Si(2), and one Si(7) atom. In the third Si site, Si(1) is bonded in a 8-coordinate geometry to one Lu(1), one Lu(2), one Lu(3), one Co(1), one Co(2), one Si(3), one Si(4), and one Si(5) atom. In the fourth Si site, Si(2) is bonded in a 9-coordinate geometry to three equivalent Lu(1), three equivalent Lu(2), one Co(2), one Si(2), and one Si(7) atom. In the fifth Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Lu(3), three equivalent Co(1), one Si(1), one Si(4), one Si(5), and one Si(6) atom. In the sixth Si site, Si(4) is bonded in a 8-coordinate geometry to one Lu(3), two equivalent Lu(1), one Co(1), one Co(2), one Si(1), one Si(3), and one Si(6) atom. In the seventh Si site, Si(5) is bonded in a 8-coordinate geometry to one Lu(3), two equivalent Lu(2), one Co(1), one Co(2), one Si(1), one Si(3), and one Si(6) atom.
Lu5(Co2Si7)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Lu sites. In the first Lu site, Lu(1) is bonded to two equivalent Co(2), one Si(1), one Si(6), two equivalent Si(4), three equivalent Si(2), and three equivalent Si(7) atoms to form a mixture of distorted corner, face, and edge-sharing LuCo2Si10 cuboctahedra. There is one shorter (3.04 Å) and one longer (3.05 Å) Lu(1)-Co(2) bond length. The Lu(1)-Si(1) bond length is 2.99 Å. The Lu(1)-Si(6) bond length is 2.95 Å. There is one shorter (2.95 Å) and one longer (2.98 Å) Lu(1)-Si(4) bond length. There are two shorter (2.86 Å) and one longer (3.07 Å) Lu(1)-Si(2) bond length. There are two shorter (2.87 Å) and one longer (3.02 Å) Lu(1)-Si(7) bond length. In the second Lu site, Lu(2) is bonded to two equivalent Co(2), one Si(1), one Si(6), two equivalent Si(5), three equivalent Si(2), and three equivalent Si(7) atoms to form a mixture of distorted corner, face, and edge-sharing LuCo2Si10 cuboctahedra. There is one shorter (3.03 Å) and one longer (3.05 Å) Lu(2)-Co(2) bond length. The Lu(2)-Si(1) bond length is 2.95 Å. The Lu(2)-Si(6) bond length is 3.00 Å. There is one shorter (2.93 Å) and one longer (3.00 Å) Lu(2)-Si(5) bond length. There are two shorter (2.86 Å) and one longer (3.05 Å) Lu(2)-Si(2) bond length. There are a spread of Lu(2)-Si(7) bond distances ranging from 2.84-3.03 Å. In the third Lu site, Lu(3) is bonded in a 18-coordinate geometry to two equivalent Co(2), four equivalent Co(1), two equivalent Si(1), two equivalent Si(4), two equivalent Si(5), two equivalent Si(6), and four equivalent Si(3) atoms. Both Lu(3)-Co(2) bond lengths are 3.02 Å. There are two shorter (3.00 Å) and two longer (3.03 Å) Lu(3)-Co(1) bond lengths. Both Lu(3)-Si(1) bond lengths are 3.00 Å. Both Lu(3)-Si(4) bond lengths are 3.01 Å. Both Lu(3)-Si(5) bond lengths are 3.01 Å. Both Lu(3)-Si(6) bond lengths are 3.00 Å. There are two shorter (2.86 Å) and two longer (2.87 Å) Lu(3)-Si(3) bond lengths. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 10-coordinate geometry to two equivalent Lu(3), one Co(1), one Si(1), one Si(4), one Si(5), one Si(6), and three equivalent Si(3) atoms. The Co(1)-Co(1) bond length is 2.79 Å. The Co(1)-Si(1) bond length is 2.46 Å. The Co(1)-Si(4) bond length is 2.46 Å. The Co(1)-Si(5) bond length is 2.46 Å. The Co(1)-Si(6) bond length is 2.46 Å. There are a spread of Co(1)-Si(3) bond distances ranging from 2.25-2.27 Å. In the second Co site, Co(2) is bonded in a 10-coordinate geometry to one Lu(3), two equivalent Lu(1), two equivalent Lu(2), one Si(1), one Si(2), one Si(4), one Si(5), and one Si(6) atom. The Co(2)-Si(1) bond length is 2.27 Å. The Co(2)-Si(2) bond length is 2.29 Å. The Co(2)-Si(4) bond length is 2.28 Å. The Co(2)-Si(5) bond length is 2.28 Å. The Co(2)-Si(6) bond length is 2.27 Å. There are seven inequivalent Si sites. In the first Si site, Si(6) is bonded in a 8-coordinate geometry to one Lu(1), one Lu(2), one Lu(3), one Co(1), one Co(2), one Si(3), one Si(4), and one Si(5) atom. The Si(6)-Si(3) bond length is 2.56 Å. The Si(6)-Si(4) bond length is 2.38 Å. The Si(6)-Si(5) bond length is 2.51 Å. In the second Si site, Si(7) is bonded in a 8-coordinate geometry to three equivalent Lu(1), three equivalent Lu(2), one Si(2), and one Si(7) atom. The Si(7)-Si(2) bond length is 2.39 Å. The Si(7)-Si(7) bond length is 2.40 Å. In the third Si site, Si(1) is bonded in a 8-coordinate geometry to one Lu(1), one Lu(2), one Lu(3), one Co(1), one Co(2), one Si(3), one Si(4), and one Si(5) atom. The Si(1)-Si(3) bond length is 2.56 Å. The Si(1)-Si(4) bond length is 2.52 Å. The Si(1)-Si(5) bond length is 2.39 Å. In the fourth Si site, Si(2) is bonded in a 9-coordinate geometry to three equivalent Lu(1), three equivalent Lu(2), one Co(2), one Si(2), and one Si(7) atom. The Si(2)-Si(2) bond length is 2.39 Å. In the fifth Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Lu(3), three equivalent Co(1), one Si(1), one Si(4), one Si(5), and one Si(6) atom. The Si(3)-Si(4) bond length is 2.55 Å. The Si(3)-Si(5) bond length is 2.55 Å. In the sixth Si site, Si(4) is bonded in a 8-coordinate geometry to one Lu(3), two equivalent Lu(1), one Co(1), one Co(2), one Si(1), one Si(3), and one Si(6) atom. In the seventh Si site, Si(5) is bonded in a 8-coordinate geometry to one Lu(3), two equivalent Lu(2), one Co(1), one Co(2), one Si(1), one Si(3), and one Si(6) atom.