Lu3Os4Si13 crystallizes in the cubic Pm-3n space group. Lu(1) is bonded in a 16-coordinate geometry to four equivalent Os(1) and twelve equivalent Si(2) atoms. Os(1) is bonded in a 9-coordinate geometry to three equivalent Lu(1) and six equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(2) is bonded in a 2-coordinate geometry to three equivalent Lu(1), two equivalent Os(1), and one Si(1) atom. In the second Si site, Si(1) is bonded in a cuboctahedral geometry to twelve equivalent Si(2) atoms.
Lu3Os4Si13 crystallizes in the cubic Pm-3n space group. Lu(1) is bonded in a 16-coordinate geometry to four equivalent Os(1) and twelve equivalent Si(2) atoms. All Lu(1)-Os(1) bond lengths are 3.10 Å. There are eight shorter (3.14 Å) and four longer (3.19 Å) Lu(1)-Si(2) bond lengths. Os(1) is bonded in a 9-coordinate geometry to three equivalent Lu(1) and six equivalent Si(2) atoms. All Os(1)-Si(2) bond lengths are 2.42 Å. There are two inequivalent Si sites. In the first Si site, Si(2) is bonded in a 2-coordinate geometry to three equivalent Lu(1), two equivalent Os(1), and one Si(1) atom. The Si(2)-Si(1) bond length is 2.77 Å. In the second Si site, Si(1) is bonded in a cuboctahedral geometry to twelve equivalent Si(2) atoms.