Materials Data on U6Al8Fe5Si9 by Materials Project

Abstract

U6Fe5Al8Si9 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. there are two inequivalent U sites. In the first U site, U is bonded in a 12-coordinate geometry to two equivalent Fe, four Al, and six Si atoms. Both U–Fe bond lengths are 3.10 Å. There are two shorter (2.95 Å) and two longer (3.22 Å) U–Al bond lengths. There are four shorter (2.88 Å) and two longer (2.89 Å) U–Si bond lengths. In the second U site, U is bonded in a 2-coordinate geometry to three equivalent Fe, six Al, and five Si atoms. There are one shorter (2.90 Å) and two longer (3.06 Å) U–Fe bond lengths. There are a spread of U–Al bond distances ranging from 3.01–3.07 Å. There are a spread of U–Si bond distances ranging from 2.90–3.20 Å. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded to four equivalent U, four equivalent Al, and four equivalent Si atoms to form distorted face-sharing FeU4Al4Si4 cuboctahedra. All Fe–Al bond lengths are 2.74 Å. All Fe–Si bond lengths are 2.48 Å. In the second Fe site, Fe is bonded in a 5-coordinate geometry to three equivalent U, one Al, and four Si atoms. The Fe–Al bond length is 2.43 Å. There are a spread of Fe–Si bond distances ranging from 2.30–2.32 Å. There are four inequivalent Al sites. In the first Al site, Al is bonded in a 12-coordinate geometry to four equivalent U, four Al, and four Si atoms. There are two shorter (2.90 Å) and two longer (2.98 Å) Al–Al bond lengths. There are two shorter (2.73 Å) and two longer (2.93 Å) Al–Si bond lengths. In the second Al site, Al is bonded in a 12-coordinate geometry to four equivalent U, four Al, and four Si atoms. Both Al–Al bond lengths are 3.07 Å. There are two shorter (2.73 Å) and two longer (2.87 Å) Al–Si bond lengths. In the third Al site, Al is bonded in a 12-coordinate geometry to four U, two equivalent Fe, two equivalent Al, and four equivalent Si atoms. All Al–Si bond lengths are 2.60 Å. In the fourth Al site, Al is bonded in a 12-coordinate geometry to four U, two equivalent Fe, two equivalent Al, and four equivalent Si atoms. All Al–Si bond lengths are 2.61 Å. There are three inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to three U, three equivalent Fe, and three Al atoms. In the second Si site, Si is bonded in a 9-coordinate geometry to four U, two Fe, and three Al atoms. In the third Si site, Si is bonded to four equivalent U and eight Al atoms to form face-sharing SiU4Al8 cuboctahedra.