Materials Data on V2FeSe4 by Materials Project
FeV2Se4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. V+2.50+ is bonded to six Se2- atoms to form distorted VSe6 octahedra that share corners with six equivalent FeSe6 octahedra, edges with six equivalent VSe6 octahedra, and a faceface with one FeSe6 octahedra. The corner-sharing octahedra tilt angles range from 50–56°. There are a spread of V–Se bond distances ranging from 2.44–2.72 Å. Fe3+ is bonded to six Se2- atoms to form FeSe6 octahedra that share corners with twelve equivalent VSe6 octahedra, edges with two equivalent FeSe6 octahedra, and faces with two equivalent VSe6 octahedra. The corner-sharing octahedra tilt angles range from 50–56°. There are two shorter (2.46 Å) and four longer (2.55 Å) Fe–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to three equivalent V+2.50+ and two equivalent Fe3+ atoms. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to three equivalent V+2.50+ and one Fe3+ atom.