DOI: 10.17188/1679409
title: Materials Data on Al2Fe(PO8)2 by Materials Project

description: FeAl2(PO7)2O2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional and consists of two hydrogen peroxide molecules and one FeAl2(PO7)2 framework. In the FeAl2(PO7)2 framework, there are two inequivalent Fe sites. In the first Fe site, Fe is bonded in a square co-planar geometry to four O atoms. There is two shorter (1.87 Å) and two longer (2.07 Å) Fe–O bond length. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with four PO4 tetrahedra, corners with two equivalent AlO5 trigonal bipyramids, and edges with two equivalent AlO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.98–2.08 Å. There are three inequivalent Al sites. In the first Al site, Al is bonded to five O atoms to form distorted AlO5 trigonal bipyramids that share a cornercorner with one FeO6 octahedra, corners with two AlO6 octahedra, and corners with three PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–60°. There are a spread of Al–O bond distances ranging from 1.82–1.90 Å. In the second Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four PO4 tetrahedra, corners with two equivalent AlO5 trigonal bipyramids, and edges with two equivalent FeO6 octahedra. There are a spread of Al–O bond distances ranging from 1.86–2.00 Å. In the third Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with two equivalent PO4 tetrahedra and corners with two equivalent AlO5 trigonal bipyramids. There are a spread of Al–O bond distances ranging from 1.84–2.02 Å. There are two inequivalent P sites. In the first P site, P is bonded to four O atoms to form PO4 tetrahedra that share a cornercorner with one FeO6 octahedra, a cornercorner with one AlO6 octahedra, and a cornercorner with one AlO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 55–60°. There are a spread of P–O bond distances ranging from 1.53–1.57 Å. In the second P site, P is bonded to four O atoms to form PO4 tetrahedra that share a cornercorner with one FeO6 octahedra, corners with two AlO6 octahedra, and corners with two equivalent AlO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 46–55°. There are a spread of P–O bond distances ranging from 1.52–1.57 Å. There are fourteen inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to one Al and one P atom. In the second O site, O is bonded in a bent 120 degrees geometry to one Fe and one P atom. In the third O site, O is bonded in a bent 120 degrees geometry to one Al and one P atom. In the fourth O site, O is bonded in a bent 120 degrees geometry to one Fe and one P atom. In the fifth O site, O is bonded in a distorted trigonal planar geometry to one Fe, one Al, and one P atom. In the sixth O site, O is bonded in a distorted bent 150 degrees geometry to one Al and one P atom. In the seventh O site, O is bonded in a bent 120 degrees geometry to one Al and one P atom. In the eighth O site, O is bonded in a bent 120 degrees geometry to one Al and one P atom. In the ninth O site, O is bonded in a bent 120 degrees geometry to two Al atoms. In the tenth O site, O is bonded in a distorted trigonal planar geometry to one Fe and two Al atoms. In the eleventh O site, O is bonded in a bent 120 degrees geometry to two O atoms. There is one shorter (1.25 Å) and one longer (1.40 Å) O–O bond length. In the twelfth O site, O is bonded in a distorted bent 120 degrees geometry to one Fe and one O atom. In the thirteenth O site, O is bonded in a single-bond geometry to one Al atom. In the fourteenth O site, O is bonded in a single-bond geometry to one O atom.