Materials Data on U2(Si2Ni)3 by Materials Project
U2(NiSi2)3 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. U5+ is bonded in a 10-coordinate geometry to ten Si+2.67- atoms. There are a spread of U–Si bond distances ranging from 3.00–3.08 Å. There are two inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded in a 5-coordinate geometry to five Si+2.67- atoms. There are one shorter (2.25 Å) and four longer (2.29 Å) Ni–Si bond lengths. In the second Ni2+ site, Ni2+ is bonded in a body-centered cubic geometry to eight Si+2.67- atoms. All Ni–Si bond lengths are 2.36 Å. There are three inequivalent Si+2.67- sites. In the first Si+2.67- site, Si+2.67- is bonded in a 4-coordinate geometry to two equivalent U5+, four Ni2+, and five Si+2.67- atoms. There are one shorter (2.54 Å) and four longer (2.81 Å) Si–Si bond lengths. In the second Si+2.67- site, Si+2.67- is bonded in a 4-coordinate geometry to two equivalent U5+, four Ni2+, and five Si+2.67- atoms. The Si–Si bond length is 2.55 Å. In the third Si+2.67- site, Si+2.67- is bonded in a 9-coordinate geometry to six equivalent U5+, one Ni2+, and two equivalent Si+2.67- atoms. Both Si–Si bond lengths are 2.33 Å.