DOE OSTI2020
(Fe(SO5)2)3AlO6(O2)3 crystallizes in the trigonal P-31c space group. The structure is zero-dimensional and consists of six oxygen molecules, two AlO6 clusters, and two Fe(SO5)2 clusters. In each AlO6 cluster, Al is bonded in an octahedral geometry to six equivalent O atoms. All Al–O bond lengths are 1.84 Å. O is bonded in a single-bond geometry to one Al atom. In each Fe(SO5)2 cluster, 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 equivalent SO4 tetrahedra. There is three shorter (1.79 Å) and three longer (1.95 Å) Fe–O bond length. In the second Fe site, Fe is bonded to six equivalent O atoms to form FeO6 octahedra that share corners with six equivalent SO4 tetrahedra. All Fe–O bond lengths are 2.01 Å. S is bonded to four O atoms to form SO4 tetrahedra that share corners with two FeO6 octahedra. The corner-sharing octahedral tilt angles are 45°. There are a spread of S–O bond distances ranging from 1.45–1.53 Å. There are five inequivalent O sites. In the first O site, O is bonded in a distorted bent 150 degrees geometry to one Fe and one S atom. In the second O site, O is bonded in a single-bond geometry to one S atom. In the third O site, O is bonded in a single-bond geometry to one S atom. In the fourth O site, O is bonded in a distorted bent 150 degrees geometry to one Fe and one S atom. In the fifth O site, O is bonded in a single-bond geometry to one Fe atom.