DOE OSTI2020
(Fe3Zn2As3O17)2(O2)9 crystallizes in the monoclinic Cm space group. The structure is three-dimensional and consists of six oxygen molecules, two trioxidane molecules, and one Fe3Zn2As3O17 framework. In the Fe3Zn2As3O17 framework, there are two inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with three AsO4 tetrahedra, edges with two equivalent FeO6 octahedra, and an edgeedge with one ZnO5 trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 1.90–2.01 Å. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with three AsO4 tetrahedra, edges with two FeO6 octahedra, and an edgeedge with one ZnO5 trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 1.95–2.21 Å. There are two inequivalent Zn sites. In the first Zn site, Zn is bonded to five O atoms to form distorted ZnO5 trigonal bipyramids that share corners with two equivalent AsO4 tetrahedra and edges with three FeO6 octahedra. There are a spread of Zn–O bond distances ranging from 1.95–2.10 Å. In the second Zn site, Zn is bonded in a distorted rectangular see-saw-like geometry to four O atoms. There are a spread of Zn–O bond distances ranging from 1.88–2.08 Å. There are two inequivalent As sites. In the first As site, As is bonded to four O atoms to form AsO4 tetrahedra that share corners with three FeO6 octahedra. The corner-sharing octahedra tilt angles range from 49–53°. There is three shorter (1.72 Å) and one longer (1.75 Å) As–O bond length. In the second As site, As is bonded to four O atoms to form AsO4 tetrahedra that share corners with three FeO6 octahedra and a cornercorner with one ZnO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 48–54°. There are a spread of As–O bond distances ranging from 1.71–1.77 Å. There are eleven inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Zn atom. In the second O site, O is bonded in a bent 120 degrees geometry to one Zn and one As atom. In the third O site, O is bonded in a bent 120 degrees geometry to one Fe and one As atom. In the fourth O site, O is bonded in a bent 120 degrees geometry to one Fe and one As atom. In the fifth O site, O is bonded in a bent 120 degrees geometry to one Fe and one As atom. In the sixth O site, O is bonded in a bent 120 degrees geometry to one Fe and one As atom. In the seventh O site, O is bonded in a distorted trigonal planar geometry to one Fe, one Zn, and one As atom. In the eighth O site, O is bonded in a bent 120 degrees geometry to one Zn and one As atom. In the ninth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Fe atoms. In the tenth O site, O is bonded in a trigonal non-coplanar geometry to two equivalent Fe and one Zn atom. In the eleventh O site, O is bonded in a distorted trigonal non-coplanar geometry to two Fe and one Zn atom.