Materials Data on Al2FeS4 by Materials Project

Abstract

FeAl2S4 crystallizes in the trigonal R-3m space group. The structure is two-dimensional and consists of three FeAl2S4 sheets oriented in the (0, 0, 1) direction. Fe2+ is bonded to six equivalent S2- atoms to form FeS6 octahedra that share corners with six equivalent AlS4 tetrahedra and edges with six equivalent FeS6 octahedra. All Fe–S bond lengths are 2.31 Å. Al3+ is bonded to four S2- atoms to form AlS4 tetrahedra that share corners with three equivalent FeS6 octahedra and corners with six equivalent AlS4 tetrahedra. The corner-sharing octahedral tilt angles are 63°. There are one shorter (2.23 Å) and three longer (2.31 Å) Al–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Al3+ atoms. In the second S2- site, S2- is bonded to three equivalent Fe2+ and one Al3+ atom to form a mixture of distorted edge and corner-sharing SAlFe3 tetrahedra.