Materials Data on Ti(CrSe2)2 by Materials Project
TiCr2Se4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Ti4+ is bonded to six Se2- atoms to form TiSe6 octahedra that share corners with twelve equivalent CrSe6 octahedra, edges with two equivalent TiSe6 octahedra, and faces with two equivalent CrSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–51°. There are two shorter (2.58 Å) and four longer (2.63 Å) Ti–Se bond lengths. Cr2+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with six equivalent TiSe6 octahedra, edges with six equivalent CrSe6 octahedra, and a faceface with one TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–51°. There are a spread of Cr–Se bond distances ranging from 2.51–2.64 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent Ti4+ and three equivalent Cr2+ atoms to form a mixture of distorted edge and corner-sharing SeTi2Cr3 trigonal bipyramids. In the second Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Ti4+ and three equivalent Cr2+ atoms.