Materials Data on Al(FeS2)2 by Materials Project

Al(FeS2)2 is Spinel-like structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Fe+2.50+ sites. In the first Fe+2.50+ site, Fe+2.50+ is bonded to four S2- atoms to form FeS4 tetrahedra that share corners with six equivalent FeS6 octahedra and corners with six equivalent AlS6 octahedra. The corner-sharing octahedra tilt angles range from 53–65°. There are two shorter (2.28 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 S2- atoms to form FeS6 octahedra that share corners with six equivalent FeS4 tetrahedra, edges with two equivalent FeS6 octahedra, and edges with four equivalent AlS6 octahedra. There are four shorter (2.30 Å) and two longer (2.31 Å) Fe–S bond lengths. Al3+ is bonded to six S2- atoms to form AlS6 octahedra that share corners with six equivalent FeS4 tetrahedra, edges with two equivalent AlS6 octahedra, and edges with four equivalent FeS6 octahedra. There are two shorter (2.39 Å) and four longer (2.41 Å) Al–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a rectangular see-saw-like geometry to three Fe+2.50+ and one Al3+ atom. In the second S2- site, S2- is bonded in a rectangular see-saw-like geometry to two Fe+2.50+ and two equivalent Al3+ atoms.