Y5(Os2Si7)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Y sites. In the first Y site, Y(1) is bonded to two equivalent Os(2), one Si(3), one Si(4), two equivalent Si(7), three equivalent Si(1), and three equivalent Si(2) atoms to form a mixture of distorted corner, edge, and face-sharing YSi10Os2 cuboctahedra. In the second Y site, Y(2) is bonded to two equivalent Os(2), one Si(3), one Si(4), two equivalent Si(5), three equivalent Si(1), and three equivalent Si(2) atoms to form a mixture of distorted corner, edge, and face-sharing YSi10Os2 cuboctahedra. In the third Y site, Y(3) is bonded in a 18-coordinate geometry to two equivalent Os(2), four equivalent Os(1), two equivalent Si(3), two equivalent Si(4), two equivalent Si(5), two equivalent Si(7), and four equivalent Si(6) atoms. There are two inequivalent Os sites. In the first Os site, Os(1) is bonded in a 7-coordinate geometry to two equivalent Y(3), one Si(3), one Si(4), one Si(5), one Si(7), and three equivalent Si(6) atoms. In the second Os site, Os(2) is bonded in a 5-coordinate geometry to one Y(3), two equivalent Y(1), two equivalent Y(2), one Si(1), one Si(3), one Si(4), one Si(5), and one Si(7) atom. There are seven inequivalent Si sites. In the first Si site, Si(7) is bonded in a 8-coordinate geometry to one Y(3), two equivalent Y(1), one Os(1), one Os(2), one Si(3), one Si(4), and one Si(6) atom. In the second Si site, Si(1) is bonded in a 9-coordinate geometry to three equivalent Y(1), three equivalent Y(2), one Os(2), one Si(1), and one Si(2) atom. In the third Si site, Si(2) is bonded in a 8-coordinate geometry to three equivalent Y(1), three equivalent Y(2), one Si(1), and one Si(2) atom. In the fourth Si site, Si(3) is bonded in a 8-coordinate geometry to one Y(1), one Y(2), one Y(3), one Os(1), one Os(2), one Si(5), one Si(6), and one Si(7) atom. In the fifth Si site, Si(4) is bonded in a 8-coordinate geometry to one Y(1), one Y(2), one Y(3), one Os(1), one Os(2), one Si(5), one Si(6), and one Si(7) atom. In the sixth Si site, Si(5) is bonded in a 8-coordinate geometry to one Y(3), two equivalent Y(2), one Os(1), one Os(2), one Si(3), one Si(4), and one Si(6) atom. In the seventh Si site, Si(6) is bonded in a 9-coordinate geometry to two equivalent Y(3), three equivalent Os(1), one Si(3), one Si(4), one Si(5), and one Si(7) atom.
Y5(Os2Si7)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Y sites. In the first Y site, Y(1) is bonded to two equivalent Os(2), one Si(3), one Si(4), two equivalent Si(7), three equivalent Si(1), and three equivalent Si(2) atoms to form a mixture of distorted corner, edge, and face-sharing YSi10Os2 cuboctahedra. There is one shorter (3.14 Å) and one longer (3.15 Å) Y(1)-Os(2) bond length. The Y(1)-Si(3) bond length is 3.10 Å. The Y(1)-Si(4) bond length is 3.09 Å. There is one shorter (3.07 Å) and one longer (3.09 Å) Y(1)-Si(7) bond length. There are two shorter (2.99 Å) and one longer (3.24 Å) Y(1)-Si(1) bond length. There are a spread of Y(1)-Si(2) bond distances ranging from 3.02-3.10 Å. In the second Y site, Y(2) is bonded to two equivalent Os(2), one Si(3), one Si(4), two equivalent Si(5), three equivalent Si(1), and three equivalent Si(2) atoms to form a mixture of distorted corner, edge, and face-sharing YSi10Os2 cuboctahedra. There is one shorter (3.14 Å) and one longer (3.16 Å) Y(2)-Os(2) bond length. The Y(2)-Si(3) bond length is 3.08 Å. The Y(2)-Si(4) bond length is 3.13 Å. There is one shorter (3.06 Å) and one longer (3.12 Å) Y(2)-Si(5) bond length. There are a spread of Y(2)-Si(1) bond distances ranging from 2.98-3.20 Å. There are a spread of Y(2)-Si(2) bond distances ranging from 2.98-3.12 Å. In the third Y site, Y(3) is bonded in a 18-coordinate geometry to two equivalent Os(2), four equivalent Os(1), two equivalent Si(3), two equivalent Si(4), two equivalent Si(5), two equivalent Si(7), and four equivalent Si(6) atoms. Both Y(3)-Os(2) bond lengths are 3.21 Å. There are two shorter (3.11 Å) and two longer (3.17 Å) Y(3)-Os(1) bond lengths. Both Y(3)-Si(3) bond lengths are 3.17 Å. Both Y(3)-Si(4) bond lengths are 3.17 Å. Both Y(3)-Si(5) bond lengths are 3.19 Å. Both Y(3)-Si(7) bond lengths are 3.18 Å. There are two shorter (2.97 Å) and two longer (2.98 Å) Y(3)-Si(6) bond lengths. There are two inequivalent Os sites. In the first Os site, Os(1) is bonded in a 7-coordinate geometry to two equivalent Y(3), one Si(3), one Si(4), one Si(5), one Si(7), and three equivalent Si(6) atoms. The Os(1)-Si(3) bond length is 2.55 Å. The Os(1)-Si(4) bond length is 2.56 Å. The Os(1)-Si(5) bond length is 2.57 Å. The Os(1)-Si(7) bond length is 2.57 Å. There are a spread of Os(1)-Si(6) bond distances ranging from 2.32-2.37 Å. In the second Os site, Os(2) is bonded in a 5-coordinate geometry to one Y(3), two equivalent Y(1), two equivalent Y(2), one Si(1), one Si(3), one Si(4), one Si(5), and one Si(7) atom. The Os(2)-Si(1) bond length is 2.37 Å. The Os(2)-Si(3) bond length is 2.42 Å. The Os(2)-Si(4) bond length is 2.42 Å. The Os(2)-Si(5) bond length is 2.44 Å. The Os(2)-Si(7) bond length is 2.44 Å. There are seven inequivalent Si sites. In the first Si site, Si(7) is bonded in a 8-coordinate geometry to one Y(3), two equivalent Y(1), one Os(1), one Os(2), one Si(3), one Si(4), and one Si(6) atom. The Si(7)-Si(3) bond length is 2.56 Å. The Si(7)-Si(4) bond length is 2.40 Å. The Si(7)-Si(6) bond length is 2.68 Å. In the second Si site, Si(1) is bonded in a 9-coordinate geometry to three equivalent Y(1), three equivalent Y(2), one Os(2), one Si(1), and one Si(2) atom. The Si(1)-Si(1) bond length is 2.45 Å. The Si(1)-Si(2) bond length is 2.45 Å. In the third Si site, Si(2) is bonded in a 8-coordinate geometry to three equivalent Y(1), three equivalent Y(2), one Si(1), and one Si(2) atom. The Si(2)-Si(2) bond length is 2.39 Å. In the fourth Si site, Si(3) is bonded in a 8-coordinate geometry to one Y(1), one Y(2), one Y(3), one Os(1), one Os(2), one Si(5), one Si(6), and one Si(7) atom. The Si(3)-Si(5) bond length is 2.41 Å. The Si(3)-Si(6) bond length is 2.69 Å. In the fifth Si site, Si(4) is bonded in a 8-coordinate geometry to one Y(1), one Y(2), one Y(3), one Os(1), one Os(2), one Si(5), one Si(6), and one Si(7) atom. The Si(4)-Si(5) bond length is 2.55 Å. The Si(4)-Si(6) bond length is 2.68 Å. In the sixth Si site, Si(5) is bonded in a 8-coordinate geometry to one Y(3), two equivalent Y(2), one Os(1), one Os(2), one Si(3), one Si(4), and one Si(6) atom. The Si(5)-Si(6) bond length is 2.66 Å. In the seventh Si site, Si(6) is bonded in a 9-coordinate geometry to two equivalent Y(3), three equivalent Os(1), one Si(3), one Si(4), one Si(5), and one Si(7) atom.