Materials Data on BaNiP2O7 by Materials Project
BaNiP2O7 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.78–3.03 Å. Ni2+ is bonded to five O2- atoms to form NiO5 trigonal bipyramids that share corners with five PO4 tetrahedra and an edgeedge with one NiO5 trigonal bipyramid. There are a spread of Ni–O bond distances ranging from 2.01–2.15 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 a cornercorner with one PO4 tetrahedra and corners with two equivalent NiO5 trigonal bipyramids. There are a spread of P–O bond distances ranging from 1.52–1.62 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one PO4 tetrahedra and corners with three equivalent NiO5 trigonal bipyramids. There are a spread of P–O bond distances ranging from 1.50–1.63 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Ba2+ and one P5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one Ni2+, and one P5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+, one Ni2+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+, one Ni2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+, two equivalent Ni2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to one Ba2+ and one P5+ atom.