Materials Data on Cr(PO4)2 by Materials Project

Abstract

Cr(PO4)2 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of two Cr(PO4)2 sheets oriented in the (0, 0, 1) direction. Cr6+ is bonded to six O2- atoms to form distorted CrO6 octahedra that share corners with five PO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 1.59–2.15 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 corners with three equivalent CrO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 27–55°. There are a spread of P–O bond distances ranging from 1.52–1.62 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 a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 31–48°. There are a spread of P–O bond distances ranging from 1.52–1.62 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one P5+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr6+ and one P5+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr6+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Cr6+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one Cr6+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr6+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the eighth O2- site, O2- is bonded in a bent 120 degrees geometry to one Cr6+ and one P5+ atom.