Materials Data on Fe2SiS4 by Materials Project

Abstract

Fe2SiS4 is Spinel-like structured and crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. there are two inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to six S2- atoms to form FeS6 octahedra that share corners with four equivalent FeS6 octahedra, corners with two equivalent SiS4 tetrahedra, edges with four equivalent FeS6 octahedra, and edges with two equivalent SiS4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. There are two shorter (2.20 Å) and four longer (2.36 Å) Fe–S bond lengths. In the second Fe2+ site, Fe2+ is bonded to six equivalent S2- atoms to form FeS6 octahedra that share corners with twelve equivalent FeS6 octahedra and corners with six equivalent SiS4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. All Fe–S bond lengths are 2.40 Å. Si4+ is bonded to four S2- atoms to form SiS4 tetrahedra that share corners with six FeS6 octahedra and edges with three equivalent FeS6 octahedra. The corner-sharing octahedra tilt angles range from 60–63°. All Si–S bond lengths are 2.15 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a rectangular see-saw-like geometry to three Fe2+ and one Si4+ atom. In the second S2- site, S2- is bonded to three equivalent Fe2+ and one Si4+ atom to form corner-sharing SFe3Si tetrahedra.