Materials Data on K4CrO4 by Materials Project
K4CrO4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.70–2.89 Å. In the second K1+ site, K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.70–3.07 Å. In the third K1+ site, K1+ is bonded to four O2- atoms to form distorted KO4 tetrahedra that share corners with four equivalent CrO4 tetrahedra, corners with two equivalent KO5 trigonal bipyramids, and edges with two equivalent KO4 tetrahedra. There are a spread of K–O bond distances ranging from 2.64–2.71 Å. In the fourth K1+ site, K1+ is bonded to five O2- atoms to form distorted KO5 trigonal bipyramids that share corners with two equivalent KO4 tetrahedra, corners with three equivalent CrO4 tetrahedra, an edgeedge with one CrO4 tetrahedra, and edges with two equivalent KO5 trigonal bipyramids. There are a spread of K–O bond distances ranging from 2.66–2.85 Å. Cr4+ is bonded to four O2- atoms to form CrO4 tetrahedra that share corners with four equivalent KO4 tetrahedra, corners with three equivalent KO5 trigonal bipyramids, and an edgeedge with one KO5 trigonal bipyramid. There are a spread of Cr–O bond distances ranging from 1.81–1.84 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to five K1+ and one Cr4+ atom to form distorted edge-sharing OK5Cr octahedra. In the second O2- site, O2- is bonded in a 1-coordinate geometry to five K1+ and one Cr4+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to five K1+ and one Cr4+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to four K1+ and one Cr4+ atom.