Materials Data on Ti2FeSe4 by Materials Project

Abstract

Ti2FeSe4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Ti3+ is bonded to six Se2- atoms to form TiSe6 octahedra that share corners with six equivalent FeSe6 octahedra, edges with six equivalent TiSe6 octahedra, and a faceface with one FeSe6 octahedra. The corner-sharing octahedra tilt angles range from 47–52°. There are a spread of Ti–Se bond distances ranging from 2.55–2.65 Å. Fe2+ is bonded to six Se2- atoms to form FeSe6 octahedra that share corners with twelve equivalent TiSe6 octahedra, edges with two equivalent FeSe6 octahedra, and faces with two equivalent TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 47–52°. There are two shorter (2.51 Å) and four longer (2.56 Å) Fe–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three equivalent Ti3+ and two equivalent Fe2+ atoms to form a mixture of distorted corner and edge-sharing SeTi3Fe2 square pyramids. In the second Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Ti3+ and one Fe2+ atom.