Materials Data on Ti2CoSe4 by Materials Project
Ti2CoSe4 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 CoSe6 octahedra, edges with six equivalent TiSe6 octahedra, and a faceface with one CoSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–50°. There are a spread of Ti–Se bond distances ranging from 2.56–2.62 Å. Co2+ is bonded to six Se2- atoms to form CoSe6 octahedra that share corners with twelve equivalent TiSe6 octahedra, edges with two equivalent CoSe6 octahedra, and faces with two equivalent TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–50°. There are two shorter (2.46 Å) and four longer (2.49 Å) Co–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three equivalent Ti3+ and two equivalent Co2+ atoms to form a mixture of distorted edge and corner-sharing SeTi3Co2 square pyramids. In the second Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to three equivalent Ti3+ and one Co2+ atom.