Materials Data on FeBi4S7 by Materials Project
FeBi4S7 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Fe2+ is bonded to six S2- atoms to form FeS6 octahedra that share corners with two equivalent BiS6 octahedra and edges with two equivalent FeS6 octahedra. The corner-sharing octahedral tilt angles are 46°. There are two shorter (2.27 Å) and four longer (2.47 Å) Fe–S bond lengths. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share a cornercorner with one FeS6 octahedra, corners with two equivalent BiS6 octahedra, and edges with five equivalent BiS6 octahedra. The corner-sharing octahedra tilt angles range from 0–46°. There are a spread of Bi–S bond distances ranging from 2.75–2.96 Å. In the second Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Bi–S bond distances ranging from 2.67–3.30 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to one Fe2+ and three Bi3+ atoms. In the second S2- site, S2- is bonded in a 5-coordinate geometry to five Bi3+ atoms. In the third S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Fe2+ and three equivalent Bi3+ atoms. In the fourth S2- site, S2- is bonded in a square co-planar geometry to four equivalent Bi3+ atoms.