Materials Data on U2FeSe5 by Materials Project
U2FeSe5 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. U+3.50+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of U–Se bond distances ranging from 2.79–3.20 Å. Fe3+ is bonded to six Se2- atoms to form corner-sharing FeSe6 octahedra. The corner-sharing octahedral tilt angles are 40°. There are four shorter (2.61 Å) and two longer (2.62 Å) Fe–Se bond lengths. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to four equivalent U+3.50+ atoms to form distorted edge-sharing SeU4 trigonal pyramids. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to three equivalent U+3.50+ and one Fe3+ atom. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to three equivalent U+3.50+ and two equivalent Fe3+ atoms.