Materials Data on Fe3(PO8)2 by Materials Project

Abstract

Fe3(PO8)2 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of two Fe3(PO8)2 sheets oriented in the (0, 1, 0) direction. 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 two equivalent PO4 tetrahedra. There are two shorter (1.88 Å) and four longer (2.17 Å) Fe–O bond lengths. In the second Fe site, Fe is bonded to six O atoms to form distorted FeO6 octahedra that share corners with four equivalent PO4 tetrahedra and an edgeedge with one FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.98–2.06 Å. P is bonded to four O atoms to form PO4 tetrahedra that share corners with five FeO6 octahedra. The corner-sharing octahedra tilt angles range from 28–55°. There is three shorter (1.54 Å) and one longer (1.58 Å) P–O bond length. There are five inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to one Fe and one P atom. In the second O site, O is bonded in a 3-coordinate geometry to two equivalent Fe and one P atom. In the third O site, O is bonded in a bent 120 degrees geometry to one Fe and one P atom. In the fourth O site, O is bonded in a bent 120 degrees geometry to one Fe and one O atom. The O–O bond length is 1.28 Å. In the fifth O site, O is bonded in a 2-coordinate geometry to one Fe and one O atom. The O–O bond length is 1.33 Å.