Materials Data on FePH4NO4F by Materials Project
NH4FePO4F crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional and consists of eight ammonium molecules and one FePO4F framework. In the FePO4F framework, there are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to four O2- and two F1- atoms to form FeO4F2 octahedra that share corners with two equivalent FeO4F2 octahedra and corners with four PO4 tetrahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of Fe–O bond distances ranging from 1.95–2.11 Å. There are one shorter (2.03 Å) and one longer (2.04 Å) Fe–F bond lengths. In the second Fe3+ site, Fe3+ is bonded to four O2- and two F1- atoms to form FeO4F2 octahedra that share corners with two equivalent FeO4F2 octahedra and corners with four PO4 tetrahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of Fe–O bond distances ranging from 1.99–2.09 Å. There is one shorter (1.98 Å) and one longer (2.01 Å) Fe–F bond length. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four FeO4F2 octahedra. The corner-sharing octahedra tilt angles range from 40–49°. There is three shorter (1.55 Å) and one longer (1.56 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four FeO4F2 octahedra. The corner-sharing octahedra tilt angles range from 40–47°. There are a spread of P–O bond distances ranging from 1.55–1.57 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Fe3+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Fe3+ and one P5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Fe3+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Fe3+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Fe3+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Fe3+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Fe3+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to one Fe3+ and one P5+ atom. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a bent 120 degrees geometry to two Fe3+ atoms. In the second F1- site, F1- is bonded in a bent 120 degrees geometry to two Fe3+ atoms.