Materials Data on VFe3(PO4)4 by Materials Project
VFe3(PO4)4 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. V3+ is bonded to six O2- atoms to form VO6 octahedra that share corners with four equivalent FeO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of V–O bond distances ranging from 1.97–2.13 Å. There are three inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four equivalent FeO6 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 Fe–O bond distances ranging from 1.93–2.16 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four equivalent FeO6 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 Fe–O bond distances ranging from 1.93–2.17 Å. In the third Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four equivalent VO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Fe–O bond distances ranging from 1.93–2.15 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 a cornercorner with one VO6 octahedra, corners with three FeO6 octahedra, and an edgeedge with one VO6 octahedra. The corner-sharing octahedra tilt angles range from 40–57°. 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 a cornercorner with one VO6 octahedra, corners with three FeO6 octahedra, and an edgeedge with one FeO6 octahedra. The corner-sharing octahedra tilt angles range from 38–57°. There are a spread of P–O bond distances ranging from 1.52–1.58 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four FeO6 octahedra and an edgeedge with one FeO6 octahedra. The corner-sharing octahedra tilt angles range from 40–57°. There are a spread of P–O bond distances ranging from 1.52–1.58 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent VO6 octahedra, corners with two FeO6 octahedra, and an edgeedge with one FeO6 octahedra. The corner-sharing octahedra tilt angles range from 40–58°. There is two shorter (1.53 Å) and two longer (1.58 Å) P–O bond length. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one V3+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Fe3+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Fe3+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Fe3+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one V3+, one Fe3+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two Fe3+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to two Fe3+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one V3+, one Fe3+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to one V3+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Fe3+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe3+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe3+ and one P5+ atom.