Materials Data on U2Si3Ni by Materials Project

Abstract

U2NiSi3 crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. there are two inequivalent U5+ sites. In the first U5+ site, U5+ is bonded in a distorted q4 geometry to ten Si4- atoms. There are four shorter (3.00 Å) and six longer (3.03 Å) U–Si bond lengths. In the second U5+ site, U5+ is bonded to eight Si4- atoms to form a mixture of distorted corner, edge, and face-sharing USi8 hexagonal bipyramids. There are a spread of U–Si bond distances ranging from 2.95–2.99 Å. Ni2+ is bonded in a trigonal planar geometry to three Si4- atoms. There are one shorter (2.24 Å) and two longer (2.27 Å) Ni–Si bond lengths. There are three inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 9-coordinate geometry to six U5+ and three Si4- atoms. There are one shorter (2.33 Å) and two longer (2.34 Å) Si–Si bond lengths. In the second Si4- site, Si4- is bonded in a 9-coordinate geometry to six U5+, two equivalent Ni2+, and one Si4- atom. In the third Si4- site, Si4- is bonded in a 9-coordinate geometry to six U5+, one Ni2+, and two equivalent Si4- atoms.