Materials Data on Ca(FeS2)4 by Materials Project
Ca(FeS2)4 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Ca2+ is bonded in a 6-coordinate geometry to six equivalent S+1.50- atoms. All Ca–S bond lengths are 2.80 Å. There are two inequivalent Fe+2.50+ sites. In the first Fe+2.50+ site, Fe+2.50+ is bonded to six S+1.50- atoms to form edge-sharing FeS6 octahedra. There are four shorter (2.29 Å) and two longer (2.30 Å) Fe–S bond lengths. In the second Fe+2.50+ site, Fe+2.50+ is bonded to six equivalent S+1.50- atoms to form edge-sharing FeS6 octahedra. All Fe–S bond lengths are 2.26 Å. There are two inequivalent S+1.50- sites. In the first S+1.50- site, S+1.50- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Fe+2.50+ atoms. In the second S+1.50- site, S+1.50- is bonded in a distorted T-shaped geometry to three equivalent Fe+2.50+ atoms.