Materials Data on MnCr3(PO4)4 by Materials Project
Cr3Mn(PO4)4 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are three inequivalent Cr+3.33+ sites. In the first Cr+3.33+ site, Cr+3.33+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four equivalent CrO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. There are a spread of Cr–O bond distances ranging from 1.96–2.10 Å. In the second Cr+3.33+ site, Cr+3.33+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four equivalent MnO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–50°. There are a spread of Cr–O bond distances ranging from 1.98–2.08 Å. In the third Cr+3.33+ site, Cr+3.33+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four equivalent CrO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. There are a spread of Cr–O bond distances ranging from 1.96–2.09 Å. Mn2+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with four equivalent CrO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–50°. There are a spread of Mn–O bond distances ranging from 1.90–2.26 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 CrO6 octahedra, corners with two equivalent MnO6 octahedra, and an edgeedge with one CrO6 octahedra. The corner-sharing octahedra tilt angles range from 44–56°. There is two shorter (1.52 Å) and two longer (1.59 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four CrO6 octahedra and an edgeedge with one CrO6 octahedra. The corner-sharing octahedra tilt angles range from 46–57°. 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 a cornercorner with one MnO6 octahedra, corners with three CrO6 octahedra, and an edgeedge with one MnO6 octahedra. The corner-sharing octahedra tilt angles range from 40–54°. There are a spread of P–O bond distances ranging from 1.52–1.57 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one MnO6 octahedra, corners with three CrO6 octahedra, and an edgeedge with one CrO6 octahedra. The corner-sharing octahedra tilt angles range from 46–57°. There are a spread of P–O bond distances ranging from 1.52–1.59 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr+3.33+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cr+3.33+, one Mn2+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr+3.33+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one Mn2+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr+3.33+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr+3.33+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr+3.33+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Cr+3.33+, one Mn2+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr+3.33+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr+3.33+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cr+3.33+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mn2+ and one P5+ atom.