DOE OSTI2020
(Cr2FeO8)2N2 crystallizes in the monoclinic P2_1 space group. The structure is two-dimensional and consists of four ammonia molecules and two Cr2FeO8 sheets oriented in the (0, 1, 0) direction. In each Cr2FeO8 sheet, there are four inequivalent Cr4+ sites. In the first Cr4+ site, Cr4+ is bonded to four O2- atoms to form CrO4 tetrahedra that share corners with three FeO6 octahedra. The corner-sharing octahedra tilt angles range from 29–45°. There are a spread of Cr–O bond distances ranging from 1.60–1.70 Å. In the second Cr4+ site, Cr4+ is bonded to four O2- atoms to form CrO4 tetrahedra that share corners with three FeO6 octahedra. The corner-sharing octahedra tilt angles range from 27–45°. There are a spread of Cr–O bond distances ranging from 1.60–1.70 Å. In the third Cr4+ site, Cr4+ is bonded to four O2- atoms to form CrO4 tetrahedra that share corners with three FeO6 octahedra. The corner-sharing octahedra tilt angles range from 9–42°. There are a spread of Cr–O bond distances ranging from 1.61–1.69 Å. In the fourth Cr4+ site, Cr4+ is bonded to four O2- atoms to form CrO4 tetrahedra that share corners with three FeO6 octahedra. The corner-sharing octahedra tilt angles range from 9–42°. There are a spread of Cr–O bond distances ranging from 1.61–1.69 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. There are a spread of Fe–O bond distances ranging from 1.99–2.03 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six CrO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.98–2.03 Å. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one Cr4+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one Cr4+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one Cr4+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one Cr4+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr4+ and one Fe3+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr4+ and one Fe3+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr4+ and one Fe3+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr4+ and one Fe3+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr4+ and one Fe3+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr4+ and one Fe3+ atom. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr4+ and one Fe3+ atom. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr4+ and one Fe3+ atom. In the thirteenth O2- site, O2- is bonded in a linear geometry to one Cr4+ and one Fe3+ atom. In the fourteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr4+ and one Fe3+ atom. In the fifteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr4+ and one Fe3+ atom. In the sixteenth O2- site, O2- is bonded in a linear geometry to one Cr4+ and one Fe3+ atom.