Materials Data on Ba(AlS2)2 by Materials Project
BaAl2S4 crystallizes in the cubic Pa-3 space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six S2- atoms. There are three shorter (3.22 Å) and three longer (3.30 Å) Ba–S bond lengths. In the second Ba2+ site, Ba2+ is bonded to twelve S2- atoms to form BaS12 cuboctahedra that share corners with twelve equivalent AlS4 tetrahedra and edges with six equivalent AlS4 tetrahedra. There are six shorter (3.62 Å) and six longer (3.64 Å) Ba–S bond lengths. Al3+ is bonded to four S2- atoms to form AlS4 tetrahedra that share corners with two equivalent BaS12 cuboctahedra, corners with four equivalent AlS4 tetrahedra, and an edgeedge with one BaS12 cuboctahedra. There are a spread of Al–S bond distances ranging from 2.25–2.28 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 2-coordinate geometry to two Ba2+ and two equivalent Al3+ atoms. In the second S2- site, S2- is bonded in a 2-coordinate geometry to two Ba2+ and two equivalent Al3+ atoms.