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Materials Data on K2Cr2AsO10 by Materials Project

K2Cr2AsO10 crystallizes in the trigonal P3_1 space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded in a 7-coordinate geometry to eight O atoms. There are a spread of K–O bond distances ranging from 2.73–3.29 Å. In the second K site, K is bonded in a 9-coordinate geometry to nine O atoms. There are a spread of K–O bond distances ranging from 2.73–3.23 Å. There are two inequivalent Cr sites. In the first Cr site, Cr is bonded to four O atoms to form CrO4 tetrahedra that share a cornercorner with one AsO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 1.62–1.85 Å. In the second Cr site, Cr is bonded to four O atoms to form CrO4 tetrahedra that share a cornercorner with one AsO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 1.62–1.86 Å. As is bonded to four O atoms to form AsO4 tetrahedra that share corners with two CrO4 tetrahedra. There is two shorter (1.70 Å) and two longer (1.76 Å) As–O bond length. There are ten inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to two K and one Cr atom. In the second O site, O is bonded in a distorted single-bond geometry to two K and one Cr atom. In the third O site, O is bonded in a distorted bent 120 degrees geometry to one K and one As atom. In the fourth O site, O is bonded in a distorted bent 120 degrees geometry to one K and one As atom. In the fifth O site, O is bonded in a distorted bent 120 degrees geometry to one K, one Cr, and one As atom. In the sixth O site, O is bonded in a distorted single-bond geometry to two K and one Cr atom. In the seventh O site, O is bonded in a distorted single-bond geometry to two K and one Cr atom. In the eighth O site, O is bonded in a distorted single-bond geometry to two K and one Cr atom. In the ninth O site, O is bonded in a distorted bent 120 degrees geometry to two K, one Cr, and one As atom. In the tenth O site, O is bonded in a distorted single-bond geometry to two K and one Cr atom.

36 MATERIALS SCIENCE↗

Materials Data on K3Cr2(AsO4)3 by Materials Project

K3Cr2(AsO4)3 crystallizes in the cubic Ia-3d space group. The structure is three-dimensional. K1+ is bonded in a distorted body-centered cubic geometry to eight equivalent O2- atoms. There are four shorter (2.59 Å) and four longer (2.74 Å) K–O bond lengths. Cr3+ is bonded to six equivalent O2- atoms to form CrO6 octahedra that share corners with six equivalent AsO4 tetrahedra. All Cr–O bond lengths are 2.07 Å. As5+ is bonded to four equivalent O2- atoms to form AsO4 tetrahedra that share corners with four equivalent CrO6 octahedra. The corner-sharing octahedral tilt angles are 40°. All As–O bond lengths are 1.73 Å. O2- is bonded in a 4-coordinate geometry to two equivalent K1+, one Cr3+, and one As5+ atom.

36 MATERIALS SCIENCE↗