Materials Data on Th2FeSe5 by Materials Project
Th2FeSe5 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Th4+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Th–Se bond distances ranging from 2.90–3.26 Å. Fe2+ is bonded to six Se2- atoms to form corner-sharing FeSe6 octahedra. The corner-sharing octahedral tilt angles are 38°. There are a spread of Fe–Se bond distances ranging from 2.64–2.71 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to four equivalent Th4+ atoms to form distorted edge-sharing SeTh4 trigonal pyramids. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to three equivalent Th4+ and one Fe2+ atom. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to three equivalent Th4+ and two equivalent Fe2+ atoms.