Materials Data on Rb3CrO8 by Materials Project

Abstract

Rb3CrO8 crystallizes in the tetragonal I-42m space group. The structure is three-dimensional. there are two inequivalent Rb sites. In the first Rb site, Rb is bonded in a 4-coordinate geometry to twelve O atoms. There are a spread of Rb–O bond distances ranging from 2.85–3.33 Å. In the second Rb site, Rb is bonded to eight O atoms to form RbO8 hexagonal bipyramids that share corners with four equivalent CrO8 hexagonal bipyramids, corners with four equivalent ORb3CrO trigonal bipyramids, and edges with two equivalent CrO8 hexagonal bipyramids. There are four shorter (2.90 Å) and four longer (3.03 Å) Rb–O bond lengths. Cr is bonded to eight O atoms to form distorted CrO8 hexagonal bipyramids that share corners with four equivalent RbO8 hexagonal bipyramids, corners with four equivalent ORb3CrO trigonal bipyramids, and edges with two equivalent RbO8 hexagonal bipyramids. There is four shorter (1.91 Å) and four longer (2.01 Å) Cr–O bond length. There are two inequivalent O sites. In the first O site, O is bonded in a 1-coordinate geometry to five Rb, one Cr, and one O atom. The O–O bond length is 1.45 Å. In the second O site, O is bonded to three Rb, one Cr, and one O atom to form distorted ORb3CrO trigonal bipyramids that share a cornercorner with one RbO8 hexagonal bipyramid, a cornercorner with one CrO8 hexagonal bipyramid, corners with ten equivalent ORb3CrO trigonal bipyramids, and an edgeedge with one ORb3CrO trigonal bipyramid.