Materials Data on KBa(Fe2Se3)2 by Materials Project
KBa(Fe2Se3)2 crystallizes in the orthorhombic Pmc2_1 space group. The structure is three-dimensional. K1+ is bonded in a 9-coordinate geometry to nine Se2- atoms. There are a spread of K–Se bond distances ranging from 3.43–3.94 Å. Ba2+ is bonded in a 9-coordinate geometry to nine Se2- atoms. There are a spread of Ba–Se bond distances ranging from 3.43–3.98 Å. There are two inequivalent Fe+2.25+ sites. In the first Fe+2.25+ site, Fe+2.25+ is bonded to four Se2- atoms to form a mixture of edge and corner-sharing FeSe4 tetrahedra. There are a spread of Fe–Se bond distances ranging from 2.38–2.46 Å. In the second Fe+2.25+ site, Fe+2.25+ is bonded to four Se2- atoms to form a mixture of edge and corner-sharing FeSe4 tetrahedra. There are a spread of Fe–Se bond distances ranging from 2.37–2.45 Å. There are six inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to two equivalent K1+, two equivalent Ba2+, and two equivalent Fe+2.25+ atoms. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent K1+, two equivalent Ba2+, and two equivalent Fe+2.25+ atoms. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to one K1+, two equivalent Ba2+, and two equivalent Fe+2.25+ atoms. In the fourth Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent K1+, one Ba2+, and two equivalent Fe+2.25+ atoms. In the fifth Se2- site, Se2- is bonded in a 6-coordinate geometry to two equivalent Ba2+ and four Fe+2.25+ atoms. In the sixth Se2- site, Se2- is bonded in a 6-coordinate geometry to two equivalent K1+ and four Fe+2.25+ atoms.