Materials Data on U2FeSi3 by Materials Project
U2FeSi3 crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. there are two inequivalent U+4.50+ sites. In the first U+4.50+ site, U+4.50+ is bonded in a distorted q4 geometry to ten Si4- atoms. There are a spread of U–Si bond distances ranging from 2.96–3.04 Å. In the second U+4.50+ site, U+4.50+ 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 2.90–3.00 Å. Fe3+ is bonded in a trigonal planar geometry to three Si4- atoms. There are one shorter (2.31 Å) and two longer (2.32 Å) Fe–Si bond lengths. There are three inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 9-coordinate geometry to six U+4.50+ and three Si4- atoms. There are one shorter (2.34 Å) and two longer (2.35 Å) Si–Si bond lengths. In the second Si4- site, Si4- is bonded in a 9-coordinate geometry to six U+4.50+, two equivalent Fe3+, and one Si4- atom. In the third Si4- site, Si4- is bonded in a 9-coordinate geometry to six U+4.50+, one Fe3+, and two equivalent Si4- atoms.