Materials Data on CrPO4 by Materials Project

Abstract

CrPO4 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent Cr3+ sites. In the first Cr3+ site, Cr3+ is bonded to five O2- atoms to form distorted CrO5 square pyramids that share corners with five PO4 tetrahedra and an edgeedge with one CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 1.91–2.09 Å. In the second Cr3+ site, Cr3+ is bonded in a square co-planar geometry to four O2- atoms. There is two shorter (1.90 Å) and two longer (1.97 Å) Cr–O bond length. In the third Cr3+ site, Cr3+ is bonded to six O2- atoms to form distorted CrO6 octahedra that share corners with six PO4 tetrahedra and edges with two equivalent CrO5 square pyramids. There are a spread of Cr–O bond distances ranging from 1.98–2.17 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one CrO6 octahedra and corners with two equivalent CrO5 square pyramids. The corner-sharing octahedral tilt angles are 51°. There are a spread of P–O bond distances ranging from 1.46–1.62 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent CrO6 octahedra and corners with three equivalent CrO5 square pyramids. The corner-sharing octahedra tilt angles range from 44–49°. There are a spread of P–O bond distances ranging from 1.52–1.58 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr3+ and one P5+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr3+ and one P5+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one Cr3+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to two Cr3+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr3+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two Cr3+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr3+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a single-bond geometry to one P5+ atom.