Materials Data on Cr6P7O24 by Materials Project
Cr6P7O24 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are three inequivalent Cr+2.17+ sites. In the first Cr+2.17+ site, Cr+2.17+ is bonded to five O2- atoms to form distorted CrO5 trigonal bipyramids that share corners with five PO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 2.01–2.40 Å. In the second Cr+2.17+ site, Cr+2.17+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six PO4 tetrahedra and an edgeedge with one CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.02–2.28 Å. In the third Cr+2.17+ site, Cr+2.17+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Cr–O bond distances ranging from 2.05–2.54 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent CrO6 octahedra, a cornercorner with one PO4 tetrahedra, and a cornercorner with one CrO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 17–48°. There are a spread of P–O bond distances ranging from 1.50–1.62 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four equivalent CrO6 octahedra and corners with two equivalent PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–55°. There are a spread of P–O bond distances ranging from 1.53–1.58 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one PO4 tetrahedra and corners with three equivalent CrO5 trigonal bipyramids. There are a spread of P–O bond distances ranging from 1.51–1.62 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent CrO6 octahedra, a cornercorner with one PO4 tetrahedra, and a cornercorner with one CrO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 39–46°. There are a spread of P–O bond distances ranging from 1.51–1.64 Å. There are thirteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Cr+2.17+ and one P5+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr+2.17+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr+2.17+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr+2.17+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two Cr+2.17+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two Cr+2.17+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two P5+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Cr+2.17+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr+2.17+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to two Cr+2.17+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a distorted linear geometry to one Cr+2.17+ and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr+2.17+ and one P5+ atom.