Materials Data on KCr5Se8 by Materials Project
KCr5Se8 is Orthorhombic Perovskite-like structured and crystallizes in the monoclinic C2 space group. The structure is three-dimensional. K1+ is bonded in a 10-coordinate geometry to ten Se2- atoms. There are a spread of K–Se bond distances ranging from 3.43–3.83 Å. There are three inequivalent Cr3+ sites. In the first Cr3+ site, Cr3+ is bonded to six Se2- atoms to form a mixture of edge, face, and corner-sharing CrSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–51°. There are a spread of Cr–Se bond distances ranging from 2.49–2.66 Å. In the second Cr3+ site, Cr3+ is bonded to six Se2- atoms to form a mixture of edge, face, and corner-sharing CrSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–51°. There are a spread of Cr–Se bond distances ranging from 2.49–2.65 Å. In the third Cr3+ site, Cr3+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing CrSe6 octahedra. The corner-sharing octahedral tilt angles are 49°. All Cr–Se bond lengths are 2.53 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 3-coordinate geometry to two equivalent K1+ and three equivalent Cr3+ atoms. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent K1+ and three Cr3+ atoms. In the third Se2- site, Se2- is bonded to five Cr3+ atoms to form distorted edge-sharing SeCr5 trigonal bipyramids. In the fourth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to one K1+ and four Cr3+ atoms.