Materials Data on U3Al2Si3 by Materials Project

Abstract

U3Al2Si3 crystallizes in the tetragonal I4cm space group. The structure is three-dimensional. there are two inequivalent U sites. In the first U site, U is bonded in a 6-coordinate geometry to four equivalent Al and six Si atoms. All U–Al bond lengths are 3.09 Å. There are a spread of U–Si bond distances ranging from 2.71–2.90 Å. In the second U site, U is bonded in a 8-coordinate geometry to three equivalent Al and five Si atoms. There are one shorter (3.06 Å) and two longer (3.08 Å) U–Al bond lengths. There are three shorter (2.90 Å) and two longer (3.05 Å) U–Si bond lengths. Al is bonded in a 3-coordinate geometry to five U and three equivalent Si atoms. There are two shorter (2.57 Å) and one longer (2.61 Å) Al–Si bond lengths. There are two inequivalent Si sites. In the first Si site, Si is bonded to six U atoms to form corner-sharing SiU6 octahedra. The corner-sharing octahedra tilt angles range from 0–45°. In the second Si site, Si is bonded in a 8-coordinate geometry to five U and three equivalent Al atoms.