Materials Data on CaNi3(P2O7)2 by Materials Project
CaNi3(P2O7)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ca2+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.46–2.70 Å. There are two inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six PO4 tetrahedra and edges with two NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 2.06–2.18 Å. In the second Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six PO4 tetrahedra and edges with two equivalent NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 2.06–2.14 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 four NiO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–61°. There are a spread of P–O bond distances ranging from 1.52–1.61 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with five NiO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 41–59°. There is three shorter (1.53 Å) and one longer (1.61 Å) P–O bond length. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+, one Ni2+, and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Ni2+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ni2+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Ni2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to one Ca2+, two Ni2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Ni2+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two P5+ atoms.