Materials Data on Fe(CoSe2)2 by Materials Project

Fe(CoSe2)2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. Fe3+ is bonded to six Se2- atoms to form FeSe6 octahedra that share corners with six equivalent CoSe6 octahedra, edges with two equivalent FeSe6 octahedra, edges with four equivalent CoSe6 octahedra, and a faceface with one CoSe6 octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Fe–Se bond distances ranging from 2.35–2.51 Å. There are two inequivalent Co+2.50+ sites. In the first Co+2.50+ site, Co+2.50+ is bonded to six Se2- atoms to form CoSe6 octahedra that share corners with six equivalent FeSe6 octahedra, corners with six equivalent CoSe6 octahedra, edges with two equivalent CoSe6 octahedra, a faceface with one FeSe6 octahedra, and a faceface with one CoSe6 octahedra. The corner-sharing octahedra tilt angles range from 50–54°. There are a spread of Co–Se bond distances ranging from 2.42–2.45 Å. In the second Co+2.50+ site, Co+2.50+ is bonded to six Se2- atoms to form CoSe6 octahedra that share corners with six equivalent CoSe6 octahedra, edges with two equivalent CoSe6 octahedra, edges with four equivalent FeSe6 octahedra, and a faceface with one CoSe6 octahedra. The corner-sharing octahedra tilt angles range from 50–54°. There are a spread of Co–Se bond distances ranging from 2.34–2.52 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Fe3+ and two Co+2.50+ atoms. In the second Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to one Fe3+ and three Co+2.50+ atoms. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Fe3+ and three Co+2.50+ atoms. In the fourth Se2- site, Se2- is bonded in a 5-coordinate geometry to one Fe3+ and four Co+2.50+ atoms.