Materials Data on LiCr6P7O24 by Materials Project
LiCr6P7O24 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. Li1+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There is one shorter (1.90 Å) and two longer (1.94 Å) Li–O bond length. There are three inequivalent Cr2+ sites. In the first Cr2+ site, Cr2+ is bonded to five O2- atoms to form distorted CrO5 trigonal bipyramids that share corners with five PO4 tetrahedra and edges with two equivalent CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.02–2.46 Å. In the second Cr2+ site, Cr2+ is bonded to six O2- atoms to form distorted CrO6 octahedra that share corners with six PO4 tetrahedra and edges with two CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 2.07–2.66 Å. In the third Cr2+ site, Cr2+ is bonded to six O2- atoms to form distorted CrO6 octahedra that share corners with six PO4 tetrahedra, an edgeedge with one CrO6 octahedra, and edges with two equivalent CrO5 trigonal bipyramids. There are a spread of Cr–O bond distances ranging from 2.09–2.53 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 four CrO6 octahedra, a cornercorner with one PO4 tetrahedra, and a cornercorner with one CrO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 28–58°. 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 55–59°. There are a spread of P–O bond distances ranging from 1.51–1.60 Å. In the third 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 corners with three equivalent CrO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 47–49°. 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 four CrO6 octahedra, a cornercorner with one PO4 tetrahedra, and a cornercorner with one CrO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 41–59°. There are a spread of P–O bond distances ranging from 1.52–1.64 Å. There are thirteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr2+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr2+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr2+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Li1+, two equivalent Cr2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Cr2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr2+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to two Cr2+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two Cr2+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two P5+ atoms. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Cr2+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr2+ and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Cr2+ and one P5+ atom.