Materials Data on Cr4(PO4)3 by Materials Project

Abstract

Cr4(PO4)3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Cr+2.25+ sites. In the first Cr+2.25+ site, Cr+2.25+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Cr–O bond distances ranging from 1.97–2.12 Å. In the second Cr+2.25+ site, Cr+2.25+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Cr–O bond distances ranging from 1.97–2.81 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded in a tetrahedral geometry to four O2- atoms. There is three shorter (1.56 Å) and one longer (1.57 Å) P–O bond length. In the second P5+ site, P5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of P–O bond distances ranging from 1.52–1.59 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr+2.25+ and one P5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Cr+2.25+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Cr+2.25+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr+2.25+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Cr+2.25+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two Cr+2.25+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to one Cr+2.25+ and one P5+ atom.