Materials Data on La3FeSiS7 by Materials Project
La3FeSiS7 crystallizes in the hexagonal P6_3 space group. The structure is three-dimensional. La+2.67+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of La–S bond distances ranging from 2.86–3.11 Å. Fe2+ is bonded to six equivalent S2- atoms to form face-sharing FeS6 octahedra. There are three shorter (2.59 Å) and three longer (2.60 Å) Fe–S bond lengths. Si4+ is bonded in a tetrahedral geometry to four S2- atoms. There are one shorter (2.10 Å) and three longer (2.14 Å) Si–S bond lengths. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded to three equivalent La+2.67+ and one Si4+ atom to form distorted corner-sharing SLa3Si tetrahedra. In the second S2- site, S2- is bonded in a 4-coordinate geometry to three equivalent La+2.67+ and one Si4+ atom. In the third S2- site, S2- is bonded to four equivalent La+2.67+ and two equivalent Fe2+ atoms to form distorted SLa4Fe2 pentagonal pyramids that share corners with four equivalent SLa4Fe2 pentagonal pyramids, corners with four equivalent SLa3Si tetrahedra, and faces with six equivalent SLa4Fe2 pentagonal pyramids.