Materials Data on BaAl4S7 by Materials Project
BaAl4S7 crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. Ba2+ is bonded in a 12-coordinate geometry to twelve S2- atoms. There are a spread of Ba–S bond distances ranging from 3.36–3.91 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four S2- atoms to form corner-sharing AlS4 tetrahedra. There are a spread of Al–S bond distances ranging from 2.25–2.32 Å. In the second Al3+ site, Al3+ is bonded to four S2- atoms to form corner-sharing AlS4 tetrahedra. There are a spread of Al–S bond distances ranging from 2.22–2.33 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted water-like geometry to two equivalent Ba2+ and two equivalent Al3+ atoms. In the second S2- site, S2- is bonded in a distorted water-like geometry to two equivalent Ba2+ and two Al3+ atoms. In the third S2- site, S2- is bonded in a distorted water-like geometry to two equivalent Ba2+ and two Al3+ atoms. In the fourth S2- site, S2- is bonded in a trigonal non-coplanar geometry to one Ba2+ and three Al3+ atoms.