Materials Data on NbNi3(PO4)4 by Materials Project
NbNi3(PO4)4 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. Nb5+ is bonded to six O2- atoms to form distorted NbO6 pentagonal pyramids that share corners with four equivalent NiO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–49°. There are a spread of Nb–O bond distances ranging from 1.90–2.10 Å. There are three inequivalent Ni+2.33+ sites. In the first Ni+2.33+ site, Ni+2.33+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four equivalent NiO6 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 Ni–O bond distances ranging from 1.99–2.15 Å. In the second Ni+2.33+ site, Ni+2.33+ is bonded to six O2- atoms to form distorted NiO6 octahedra that share corners with four equivalent NbO6 pentagonal pyramids, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. There are a spread of Ni–O bond distances ranging from 1.96–2.27 Å. In the third Ni+2.33+ site, Ni+2.33+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four equivalent NiO6 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 Ni–O bond distances ranging from 1.98–2.17 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 three NiO6 octahedra, a cornercorner with one NbO6 pentagonal pyramid, and an edgeedge with one NiO6 octahedra. The corner-sharing octahedra tilt angles range from 53–57°. There are a spread of P–O bond distances ranging from 1.50–1.64 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three NiO6 octahedra, a cornercorner with one NbO6 pentagonal pyramid, and an edgeedge with one NbO6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 41–58°. There are a spread of P–O bond distances ranging from 1.48–1.60 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four NiO6 octahedra and an edgeedge with one NiO6 octahedra. The corner-sharing octahedra tilt angles range from 41–55°. There are a spread of P–O bond distances ranging from 1.53–1.57 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two NiO6 octahedra, corners with two equivalent NbO6 pentagonal pyramids, and an edgeedge with one NiO6 octahedra. The corner-sharing octahedral tilt angles are 46°. There are a spread of P–O bond distances ranging from 1.50–1.63 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Nb5+ and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Ni+2.33+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ni+2.33+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ni+2.33+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Nb5+, one Ni+2.33+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ni+2.33+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ni+2.33+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two Ni+2.33+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to one Nb5+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a bent 120 degrees geometry to one Ni+2.33+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Nb5+, one Ni+2.33+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ni+2.33+ and one P5+ atom.