Materials Data on U6Fe16Si7 by Materials Project
U6Fe16Si7 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. U is bonded in a 12-coordinate geometry to eight Fe and four equivalent Si atoms. There are four shorter (2.74 Å) and four longer (2.88 Å) U–Fe bond lengths. All U–Si bond lengths are 2.94 Å. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded in a 12-coordinate geometry to three equivalent U, six Fe, and three equivalent Si atoms. There are three shorter (2.54 Å) and three longer (2.59 Å) Fe–Fe bond lengths. All Fe–Si bond lengths are 2.38 Å. In the second Fe site, Fe is bonded in a 7-coordinate geometry to three equivalent U, six Fe, and four Si atoms. All Fe–Fe bond lengths are 2.84 Å. There are one shorter (2.46 Å) and three longer (2.54 Å) Fe–Si bond lengths. There are two inequivalent Si sites. In the first Si site, Si is bonded in a body-centered cubic geometry to eight equivalent Fe atoms. In the second Si site, Si is bonded to four equivalent U and eight Fe atoms to form a mixture of face and corner-sharing SiU4Fe8 cuboctahedra.