Materials Data on MnNiP2O7 by Materials Project
MnNiP2O7 crystallizes in the triclinic P1 space group. The structure is three-dimensional. Mn2+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with six PO4 tetrahedra and edges with three equivalent NiO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.12–2.37 Å. Ni2+ is bonded to six O2- atoms to form distorted NiO6 octahedra that share corners with six PO4 tetrahedra and edges with three equivalent MnO6 octahedra. There are a spread of Ni–O bond distances ranging from 2.08–2.25 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 corners with three equivalent MnO6 octahedra, corners with three equivalent NiO6 octahedra, and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 42–63°. There is three shorter (1.54 Å) and one 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 corners with three equivalent MnO6 octahedra, corners with three equivalent NiO6 octahedra, and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 42–63°. There are a spread of P–O bond distances ranging from 1.53–1.59 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Mn2+, one Ni2+, and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Mn2+, one Ni2+, and one P5+ atom. In the third O2- site, O2- is bonded in a linear geometry to two P5+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Mn2+, one Ni2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Mn2+, one Ni2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Mn2+, one Ni2+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Mn2+, one Ni2+, and one P5+ atom.