DOI: 10.17188/1303993
title: Materials Data on Mn3NbCr2(PO4)6 by Materials Project

description: NbCr2Mn3(PO4)6 crystallizes in the trigonal R3 space group. The structure is three-dimensional. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six PO4 tetrahedra and a faceface with one CrO6 octahedra. There are three shorter (1.92 Å) and three longer (2.11 Å) Nb–O bond lengths. There are two inequivalent Cr+3.50+ sites. In the first Cr+3.50+ site, Cr+3.50+ is bonded to six O2- atoms to form distorted CrO6 octahedra that share corners with six PO4 tetrahedra, a faceface with one NbO6 octahedra, and a faceface with one MnO6 pentagonal pyramid. There are three shorter (2.10 Å) and three longer (2.19 Å) Cr–O bond lengths. In the second Cr+3.50+ site, Cr+3.50+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six PO4 tetrahedra, a faceface with one MnO6 octahedra, and a faceface with one MnO6 pentagonal pyramid. There are three shorter (2.08 Å) and three longer (2.10 Å) Cr–O bond lengths. There are three inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to six O2- atoms to form distorted MnO6 pentagonal pyramids that share corners with six PO4 tetrahedra and a faceface with one CrO6 octahedra. There are three shorter (1.99 Å) and three longer (2.17 Å) Mn–O bond lengths. In the second Mn2+ site, Mn2+ is bonded to six O2- atoms to form distorted MnO6 pentagonal pyramids that share corners with six PO4 tetrahedra and a faceface with one CrO6 octahedra. There are three shorter (2.05 Å) and three longer (2.28 Å) Mn–O bond lengths. In the third Mn2+ site, Mn2+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with six PO4 tetrahedra and a faceface with one CrO6 octahedra. There are three shorter (2.03 Å) and three longer (2.17 Å) Mn–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, a cornercorner with one MnO6 octahedra, corners with two CrO6 octahedra, and corners with two MnO6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 23–39°. There are a spread of P–O bond distances ranging from 1.50–1.60 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, a cornercorner with one MnO6 octahedra, corners with two CrO6 octahedra, and corners with two MnO6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 35–56°. There are a spread of P–O bond distances ranging from 1.50–1.64 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Mn2+ and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Cr+3.50+, one Mn2+, and one P5+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Nb5+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Cr+3.50+, one Mn2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to one Mn2+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Nb5+, one Cr+3.50+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Cr+3.50+, one Mn2+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one Mn2+ and one P5+ atom.