Materials Data on Zn3Cr6(FeO6)4 by Materials Project
Cr6Zn3(FeO6)4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are three inequivalent Cr5+ sites. In the first Cr5+ site, Cr5+ is bonded to four O2- atoms to form CrO4 tetrahedra that share corners with four FeO6 octahedra and corners with two equivalent ZnO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 23–60°. There are a spread of Cr–O bond distances ranging from 1.62–1.70 Å. In the second Cr5+ site, Cr5+ is bonded to four O2- atoms to form CrO4 tetrahedra that share corners with five FeO6 octahedra and a cornercorner with one ZnO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 46–53°. There are a spread of Cr–O bond distances ranging from 1.74–1.88 Å. In the third Cr5+ site, Cr5+ is bonded to four O2- atoms to form CrO4 tetrahedra that share corners with three FeO6 octahedra and corners with two equivalent ZnO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 17–54°. There are a spread of Cr–O bond distances ranging from 1.63–1.71 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six CrO4 tetrahedra, an edgeedge with one FeO6 octahedra, and an edgeedge with one ZnO5 trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 1.95–2.18 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six CrO4 tetrahedra, an edgeedge with one FeO6 octahedra, and an edgeedge with one ZnO5 trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 1.99–2.17 Å. There are two inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are two shorter (1.85 Å) and two longer (2.32 Å) Zn–O bond lengths. In the second Zn2+ site, Zn2+ is bonded to five O2- atoms to form ZnO5 trigonal bipyramids that share corners with five CrO4 tetrahedra and edges with two FeO6 octahedra. There are a spread of Zn–O bond distances ranging from 1.97–2.16 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Cr5+, one Fe3+, and one Zn2+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr5+ and one Fe3+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr5+ and one Zn2+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr5+ and one Zn2+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cr5+, one Fe3+, and one Zn2+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cr5+ and two equivalent Fe3+ atoms. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Cr5+, one Fe3+, and one Zn2+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Cr5+, one Fe3+, and one Zn2+ atom. In the ninth O2- site, O2- is bonded in a trigonal planar geometry to one Cr5+, one Fe3+, and one Zn2+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cr5+ and two equivalent Fe3+ atoms. In the eleventh O2- site, O2- is bonded in a distorted linear geometry to one Cr5+ and one Fe3+ atom. In the twelfth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr5+ and one Fe3+ atom.