Materials Data on Ba4Sb4Se11 by Materials Project
Ba4Sb4Se11 crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to eight Se2- atoms to form distorted BaSe8 hexagonal bipyramids that share a cornercorner with one BaSe8 hexagonal bipyramid, a cornercorner with one SbSe6 octahedra, a cornercorner with one SbSe5 square pyramid, edges with two equivalent BaSe8 hexagonal bipyramids, edges with two equivalent SbSe6 octahedra, and faces with three equivalent BaSe8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 55°. There are a spread of Ba–Se bond distances ranging from 3.32–3.61 Å. In the second Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine Se2- atoms. There are a spread of Ba–Se bond distances ranging from 3.39–3.74 Å. There are four inequivalent Sb+3.50+ sites. In the first Sb+3.50+ site, Sb+3.50+ is bonded to six Se2- atoms to form distorted SbSe6 octahedra that share corners with two equivalent BaSe8 hexagonal bipyramids, corners with two equivalent SbSe5 square pyramids, edges with four equivalent BaSe8 hexagonal bipyramids, and an edgeedge with one SbSe6 octahedra. There are a spread of Sb–Se bond distances ranging from 2.61–3.25 Å. In the second Sb+3.50+ site, Sb+3.50+ is bonded in a 3-coordinate geometry to three Se2- atoms. All Sb–Se bond lengths are 2.62 Å. In the third Sb+3.50+ site, Sb+3.50+ is bonded to five Se2- atoms to form SbSe5 square pyramids that share corners with two equivalent BaSe8 hexagonal bipyramids and corners with two equivalent SbSe6 octahedra. The corner-sharing octahedral tilt angles are 22°. There are a spread of Sb–Se bond distances ranging from 2.58–3.06 Å. In the fourth Sb+3.50+ site, Sb+3.50+ is bonded in a distorted trigonal non-coplanar geometry to three Se2- atoms. There are one shorter (2.61 Å) and two longer (2.65 Å) Sb–Se bond lengths. There are nine inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to four equivalent Ba2+ and one Se2- atom. The Se–Se bond length is 2.42 Å. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to three Ba2+ and two Sb+3.50+ atoms. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to four equivalent Ba2+ and one Sb+3.50+ atom. In the fourth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ba2+ and two equivalent Sb+3.50+ atoms. In the fifth Se2- site, Se2- is bonded in a 6-coordinate geometry to four equivalent Ba2+, one Sb+3.50+, and one Se2- atom. The Se–Se bond length is 2.48 Å. In the sixth Se2- site, Se2- is bonded to four equivalent Ba2+ and one Sb+3.50+ atom to form a mixture of distorted edge and corner-sharing SeBa4Sb square pyramids. In the seventh Se2- site, Se2- is bonded in a 4-coordinate geometry to one Ba2+ and three Sb+3.50+ atoms. In the eighth Se2- site, Se2- is bonded to four Ba2+ and one Sb+3.50+ atom to form a mixture of distorted edge and corner-sharing SeBa4Sb square pyramids. In the ninth Se2- site, Se2- is bonded in a 5-coordinate geometry to four Ba2+ and one Sb+3.50+ atom.