Materials Data on Ba4SnGe2(S4Br)2 by Materials Project
Ba4Ge2SnS8Br2 crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to six S2- and two equivalent Br1- atoms. There are a spread of Ba–S bond distances ranging from 3.24–3.53 Å. There are one shorter (3.33 Å) and one longer (3.50 Å) Ba–Br bond lengths. In the second Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to six S2- and two equivalent Br1- atoms. There are a spread of Ba–S bond distances ranging from 3.29–3.55 Å. There are one shorter (3.35 Å) and one longer (3.45 Å) Ba–Br bond lengths. Sn2+ is bonded to five S2- and one Br1- atom to form distorted SnS5Br octahedra that share corners with three equivalent GeS4 tetrahedra and an edgeedge with one GeS4 tetrahedra. There are a spread of Sn–S bond distances ranging from 2.67–3.16 Å. The Sn–Br bond length is 3.12 Å. There are two inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four S2- atoms to form GeS4 tetrahedra that share an edgeedge with one SnS5Br octahedra. There are a spread of Ge–S bond distances ranging from 2.21–2.24 Å. In the second Ge4+ site, Ge4+ is bonded to four S2- atoms to form GeS4 tetrahedra that share corners with three equivalent SnS5Br octahedra. The corner-sharing octahedra tilt angles range from 8–16°. There are a spread of Ge–S bond distances ranging from 2.20–2.33 Å. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to two Ba2+, one Sn2+, and one Ge4+ atom. In the second S2- site, S2- is bonded in a 4-coordinate geometry to two Ba2+, one Sn2+, and one Ge4+ atom. In the third S2- site, S2- is bonded in a 5-coordinate geometry to four equivalent Ba2+ and one Ge4+ atom. In the fourth S2- site, S2- is bonded to four equivalent Ba2+, one Sn2+, and one Ge4+ atom to form distorted corner-sharing SBa4SnGe octahedra. The corner-sharing octahedral tilt angles are 30°. In the fifth S2- site, S2- is bonded in a 5-coordinate geometry to four Ba2+ and one Ge4+ atom. In the sixth S2- site, S2- is bonded in a 5-coordinate geometry to four Ba2+ and one Ge4+ atom. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 5-coordinate geometry to four equivalent Ba2+ and one Sn2+ atom. In the second Br1- site, Br1- is bonded in a distorted square co-planar geometry to four equivalent Ba2+ atoms.