Materials Data on KCr(MoO4)2 by Materials Project

Abstract

KCr(MoO4)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. K1+ is bonded to eight O2- atoms to form distorted KO8 hexagonal bipyramids that share corners with four equivalent MoO4 tetrahedra, edges with two equivalent KO8 hexagonal bipyramids, edges with two equivalent CrO6 octahedra, and edges with two equivalent MoO4 tetrahedra. There are a spread of K–O bond distances ranging from 2.79–3.07 Å. Mo6+ is bonded to four O2- atoms to form MoO4 tetrahedra that share corners with two equivalent KO8 hexagonal bipyramids, corners with three equivalent CrO6 octahedra, and an edgeedge with one KO8 hexagonal bipyramid. The corner-sharing octahedra tilt angles range from 25–53°. There are a spread of Mo–O bond distances ranging from 1.75–1.83 Å. Cr3+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six equivalent MoO4 tetrahedra and edges with two equivalent KO8 hexagonal bipyramids. There are a spread of Cr–O bond distances ranging from 1.99–2.03 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+, one Mo6+, and one Cr3+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent K1+ and one Mo6+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Mo6+ and one Cr3+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one K1+, one Mo6+, and one Cr3+ atom.