Materials Data on K2ZnCr2(H2O5)2 by Materials Project
K2Cr2Zn(H2O5)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.80–3.33 Å. Cr6+ is bonded to four O2- atoms to form CrO4 tetrahedra that share corners with two equivalent ZnO6 octahedra. The corner-sharing octahedra tilt angles range from 47–48°. There are a spread of Cr–O bond distances ranging from 1.65–1.70 Å. Zn2+ is bonded to six O2- atoms to form ZnO6 octahedra that share corners with four equivalent CrO4 tetrahedra. There are a spread of Zn–O bond distances ranging from 2.07–2.15 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent K1+, one Cr6+, and one Zn2+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Cr6+, and one Zn2+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent K1+ and one Cr6+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to two equivalent K1+ and one Cr6+ atom. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to one K1+, one Zn2+, and two H1+ atoms.