Materials Data on Ti(FeSe2)2 by Materials Project

Abstract

Ti(FeSe2)2 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of one Ti(FeSe2)2 sheet oriented in the (0, 0, 1) direction. Ti4+ is bonded to six Se2- atoms to form distorted TiSe6 octahedra that share corners with two equivalent FeSe5 trigonal bipyramids, edges with two equivalent TiSe6 octahedra, and faces with four equivalent FeSe5 trigonal bipyramids. There are a spread of Ti–Se bond distances ranging from 2.57–2.84 Å. Fe2+ is bonded to five Se2- atoms to form FeSe5 trigonal bipyramids that share a cornercorner with one TiSe6 octahedra, corners with two equivalent FeSe5 trigonal bipyramids, edges with three equivalent FeSe5 trigonal bipyramids, and faces with two equivalent TiSe6 octahedra. The corner-sharing octahedral tilt angles are 73°. There are a spread of Fe–Se bond distances ranging from 2.32–2.54 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 3-coordinate geometry to one Ti4+ and three equivalent Fe2+ atoms. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to two equivalent Ti4+ and two equivalent Fe2+ atoms.