Materials Data on Fe(NiSe2)2 by Materials Project

Abstract

Fe(NiSe2)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Fe3+ is bonded to six Se2- atoms to form FeSe6 octahedra that share corners with twelve equivalent NiSe6 octahedra, edges with two equivalent FeSe6 octahedra, and faces with two equivalent NiSe6 octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are two shorter (2.43 Å) and four longer (2.48 Å) Fe–Se bond lengths. Ni+2.50+ is bonded to six Se2- atoms to form NiSe6 octahedra that share corners with six equivalent FeSe6 octahedra, edges with six equivalent NiSe6 octahedra, and a faceface with one FeSe6 octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Ni–Se bond distances ranging from 2.39–2.52 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to one Fe3+ and three equivalent Ni+2.50+ atoms. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Fe3+ and three equivalent Ni+2.50+ atoms.