DOE OSTI2020
U2Os3Si5 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. U5+ is bonded in a 8-coordinate geometry to six Os2- and ten Si+0.80- atoms. There are a spread of U–Os bond distances ranging from 3.04–3.41 Å. There are a spread of U–Si bond distances ranging from 2.96–3.32 Å. There are two inequivalent Os2- sites. In the first Os2- site, Os2- is bonded in a 6-coordinate geometry to four equivalent U5+ and six Si+0.80- atoms. There are a spread of Os–Si bond distances ranging from 2.41–2.63 Å. In the second Os2- site, Os2- is bonded in a 5-coordinate geometry to four equivalent U5+ and five Si+0.80- atoms. There are a spread of Os–Si bond distances ranging from 2.36–2.49 Å. There are four inequivalent Si+0.80- sites. In the first Si+0.80- site, Si+0.80- is bonded in a 9-coordinate geometry to four equivalent U5+, three Os2-, and two Si+0.80- atoms. There are one shorter (2.51 Å) and one longer (2.57 Å) Si–Si bond lengths. In the second Si+0.80- site, Si+0.80- is bonded in a 3-coordinate geometry to four equivalent U5+, three Os2-, and two equivalent Si+0.80- atoms. In the third Si+0.80- site, Si+0.80- is bonded in a 4-coordinate geometry to four equivalent U5+ and four equivalent Os2- atoms. In the fourth Si+0.80- site, Si+0.80- is bonded in a 3-coordinate geometry to four equivalent U5+, three Os2-, and two equivalent Si+0.80- atoms.