Materials Data on TiFe(PO4)2 by Materials Project
TiFe(PO4)2 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. Ti4+ is bonded to six O2- atoms to form distorted TiO6 pentagonal pyramids 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 47–50°. There are a spread of Ti–O bond distances ranging from 1.90–2.06 Å. Fe2+ is bonded to six O2- atoms to form distorted FeO6 octahedra that share corners with four equivalent TiO6 pentagonal pyramids, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 2.02–2.33 Å. There are two 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 FeO6 octahedra, corners with three equivalent TiO6 pentagonal pyramids, and an edgeedge with one FeO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of P–O bond distances ranging from 1.49–1.58 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent FeO6 octahedra, a cornercorner with one TiO6 pentagonal pyramid, and an edgeedge with one TiO6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 32–61°. There are a spread of P–O bond distances ranging from 1.49–1.58 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ti4+ and one P5+ atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one Fe2+ and one P5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Ti4+, one Fe2+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ti4+, one Fe2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ti4+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe2+ and one P5+ atom.