Materials Data on KAlCr2O10 by Materials Project
KCr2AlO10 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. K is bonded in a 10-coordinate geometry to ten O atoms. There are a spread of K–O bond distances ranging from 2.85–3.15 Å. Cr is bonded to four O atoms to form CrO4 tetrahedra that share corners with two equivalent AlO6 octahedra. The corner-sharing octahedral tilt angles are 33°. There are a spread of Cr–O bond distances ranging from 1.61–1.73 Å. Al is bonded to six O atoms to form AlO6 octahedra that share corners with four equivalent CrO4 tetrahedra. There is two shorter (1.86 Å) and four longer (1.89 Å) Al–O bond length. There are four inequivalent O sites. In the first O site, O is bonded in a distorted bent 150 degrees geometry to one K, one Cr, and one Al atom. In the second O site, O is bonded in a distorted single-bond geometry to one K and one Cr atom. In the third O site, O is bonded in a single-bond geometry to two equivalent K and one Cr atom. In the fourth O site, O is bonded in a single-bond geometry to one Al atom.