DOI: 10.17188/1305515
title: Materials Data on Ti3NbFe2(PO4)6 by Materials Project

description: Ti3NbFe2(PO4)6 crystallizes in the trigonal R3 space group. The structure is three-dimensional. there are three inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six PO4 tetrahedra and a faceface with one FeO6 octahedra. There are three shorter (1.94 Å) and three longer (2.11 Å) Ti–O bond lengths. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six PO4 tetrahedra and a faceface with one FeO6 octahedra. There are three shorter (1.94 Å) and three longer (2.08 Å) Ti–O bond lengths. In the third Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six PO4 tetrahedra and a faceface with one FeO6 octahedra. There are three shorter (1.95 Å) and three longer (2.10 Å) Ti–O bond lengths. Nb2+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six PO4 tetrahedra and a faceface with one FeO6 octahedra. There are three shorter (2.01 Å) and three longer (2.13 Å) Nb–O bond lengths. There are two inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to six O2- atoms to form distorted FeO6 octahedra that share corners with six PO4 tetrahedra, a faceface with one TiO6 octahedra, and a faceface with one NbO6 octahedra. There are three shorter (2.18 Å) and three longer (2.28 Å) Fe–O bond lengths. In the second Fe2+ site, Fe2+ is bonded to six O2- atoms to form distorted FeO6 octahedra that share corners with six PO4 tetrahedra and faces with two TiO6 octahedra. There are three shorter (2.23 Å) and three longer (2.24 Å) Fe–O bond lengths. 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 NbO6 octahedra, corners with two FeO6 octahedra, and corners with three TiO6 octahedra. The corner-sharing octahedra tilt angles range from 24–48°. There are a spread of P–O bond distances ranging from 1.53–1.56 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one NbO6 octahedra, corners with two FeO6 octahedra, and corners with three TiO6 octahedra. The corner-sharing octahedra tilt angles range from 26–48°. There are a spread of P–O bond distances ranging from 1.53–1.57 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Ti4+ and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Ti4+, one Fe2+, and one P5+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Nb2+ 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 3-coordinate geometry to one Nb2+, one Fe2+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Ti4+, one Fe2+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ti4+ and one P5+ atom.