Materials Data on Na5FeS4 by Materials Project
Na5FeS4 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. there are five inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Na–S bond distances ranging from 2.87–3.24 Å. In the second Na1+ site, Na1+ is bonded to four S2- atoms to form distorted NaS4 tetrahedra that share corners with two equivalent FeS4 tetrahedra, corners with five NaS4 tetrahedra, corners with three equivalent NaS4 trigonal pyramids, and an edgeedge with one FeS4 tetrahedra. There are a spread of Na–S bond distances ranging from 2.73–2.82 Å. In the third Na1+ site, Na1+ is bonded in a 4-coordinate geometry to four S2- atoms. There are a spread of Na–S bond distances ranging from 2.85–2.91 Å. In the fourth Na1+ site, Na1+ is bonded to four S2- atoms to form distorted NaS4 tetrahedra that share corners with two equivalent FeS4 tetrahedra, corners with three equivalent NaS4 tetrahedra, corners with six equivalent NaS4 trigonal pyramids, an edgeedge with one NaS4 tetrahedra, and an edgeedge with one FeS4 tetrahedra. There are a spread of Na–S bond distances ranging from 2.72–2.99 Å. In the fifth Na1+ site, Na1+ is bonded to four S2- atoms to form distorted NaS4 trigonal pyramids that share corners with two equivalent FeS4 tetrahedra, corners with nine NaS4 tetrahedra, corners with two equivalent NaS4 trigonal pyramids, and an edgeedge with one FeS4 tetrahedra. There are a spread of Na–S bond distances ranging from 2.88–2.96 Å. Fe3+ is bonded to four S2- atoms to form FeS4 tetrahedra that share corners with four NaS4 tetrahedra, corners with two equivalent NaS4 trigonal pyramids, edges with two NaS4 tetrahedra, and an edgeedge with one NaS4 trigonal pyramid. There are three shorter (2.29 Å) and one longer (2.30 Å) Fe–S bond lengths. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a 7-coordinate geometry to six Na1+ and one Fe3+ atom. In the second S2- site, S2- is bonded to five Na1+ and one Fe3+ atom to form distorted corner-sharing SNa5Fe octahedra. The corner-sharing octahedral tilt angles are 74°. In the third S2- site, S2- is bonded in a 6-coordinate geometry to five Na1+ and one Fe3+ atom. In the fourth S2- site, S2- is bonded in a 7-coordinate geometry to six Na1+ and one Fe3+ atom.