Materials Data on Ba6Fe25S27 by Materials Project
Ba6Fe25S27 crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Ba is bonded in a 9-coordinate geometry to nine S atoms. There are a spread of Ba–S bond distances ranging from 3.01–3.23 Å. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded to four S atoms to form FeS4 tetrahedra that share a cornercorner with one FeS6 octahedra, corners with five equivalent FeS4 tetrahedra, and edges with three equivalent FeS4 tetrahedra. The corner-sharing octahedral tilt angles are 57°. There are a spread of Fe–S bond distances ranging from 2.15–2.21 Å. In the second Fe site, Fe is bonded to six equivalent S atoms to form corner-sharing FeS6 octahedra. All Fe–S bond lengths are 2.33 Å. There are four inequivalent S sites. In the first S site, S is bonded in a 5-coordinate geometry to five Fe atoms. In the second S site, S is bonded to three equivalent Ba and three equivalent Fe atoms to form distorted SBa3Fe3 octahedra that share corners with three equivalent SBa3Fe3 octahedra, edges with three equivalent SBa3Fe3 octahedra, and a faceface with one SBa6 octahedra. The corner-sharing octahedral tilt angles are 29°. In the third S site, S is bonded in a 6-coordinate geometry to two equivalent Ba and four equivalent Fe atoms. In the fourth S site, S is bonded to six equivalent Ba atoms to form face-sharing SBa6 octahedra.