Materials Data on NiP2O7 by Materials Project

NiP2O7 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Ni4+ sites. In the first Ni4+ site, Ni4+ is bonded to six O2- atoms to form NiO6 octahedra that share a cornercorner with one NiO6 octahedra and corners with six PO4 tetrahedra. The corner-sharing octahedral tilt angles are 57°. There are a spread of Ni–O bond distances ranging from 2.01–2.18 Å. In the second Ni4+ site, Ni4+ is bonded to six O2- atoms to form NiO6 octahedra that share a cornercorner with one NiO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 57°. There are a spread of Ni–O bond distances ranging from 1.94–2.08 Å. In the third Ni4+ site, Ni4+ is bonded to six O2- atoms to form NiO6 octahedra that share a cornercorner with one NiO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 57°. There are a spread of Ni–O bond distances ranging from 1.94–2.11 Å. In the fourth Ni4+ site, Ni4+ is bonded to six O2- atoms to form NiO6 octahedra that share a cornercorner with one NiO6 octahedra and corners with six PO4 tetrahedra. The corner-sharing octahedral tilt angles are 57°. There are a spread of Ni–O bond distances ranging from 1.96–2.11 Å. There are eight inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two NiO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 35–41°. There are a spread of P–O bond distances ranging from 1.51–1.63 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two NiO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 34–41°. There are a spread of P–O bond distances ranging from 1.52–1.63 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three NiO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 33–46°. There are a spread of P–O bond distances ranging from 1.50–1.61 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three NiO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–49°. There are a spread of P–O bond distances ranging from 1.51–1.61 Å. In the fifth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two NiO6 octahedra, a cornercorner with one PO4 tetrahedra, and an edgeedge with one NiO6 octahedra. The corner-sharing octahedra tilt angles range from 47–49°. There are a spread of P–O bond distances ranging from 1.50–1.60 Å. In the sixth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three NiO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 40–46°. There are a spread of P–O bond distances ranging from 1.53–1.62 Å. In the seventh P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three NiO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 33–47°. There are a spread of P–O bond distances ranging from 1.52–1.61 Å. In the eighth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two NiO6 octahedra, a cornercorner with one PO4 tetrahedra, and an edgeedge with one NiO6 octahedra. The corner-sharing octahedra tilt angles range from 45–47°. There are a spread of P–O bond distances ranging from 1.51–1.60 Å. There are twenty-eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Ni4+ and one P5+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one P5+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ni4+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ni4+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two P5+ atoms. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Ni4+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ni4+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ni4+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two P5+ atoms. In the eleventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ni4+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to two Ni4+ and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ni4+ and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ni4+ and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ni4+ and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ni4+ and one P5+ atom. In the seventeenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ni4+ and one P5+ atom. In the eighteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ni4+ and one P5+ atom. In the nineteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ni4+ and one P5+ atom. In the twentieth O2- site, O2- is bonded in a 3-coordinate geometry to two Ni4+ and one P5+ atom. In the twenty-first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ni4+ and one P5+ atom. In the twenty-second O2- site, O2- is bonded in an L-shaped geometry to one Ni4+ and one P5+ atom. In the twenty-third O2- site, O2- is bonded in a single-bond geometry to one P5+ atom. In the twenty-fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the twenty-fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ni4+ and one P5+ atom. In the twenty-sixth O2- site, O2- is bonded in an L-shaped geometry to one Ni4+ and one P5+ atom. In the twenty-seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ni4+ and one P5+ atom. In the twenty-eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ni4+ and one P5+ atom.