DOI: 10.17188/1318515
title: Materials Data on CaV2Ni2(P2O9)2 by Materials Project

description: CaV2Ni2(P2O9)2 crystallizes in the orthorhombic Pmc2_1 space group. The structure is three-dimensional. Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.29–2.62 Å. There are two inequivalent V5+ sites. In the first V5+ site, V5+ is bonded to six O2- atoms to form VO6 octahedra that share corners with two equivalent NiO6 octahedra, corners with three PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. There are a spread of V–O bond distances ranging from 1.69–2.04 Å. In the second V5+ site, V5+ is bonded to six O2- atoms to form VO6 octahedra that share corners with two equivalent NiO6 octahedra, corners with three PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. There are a spread of V–O bond distances ranging from 1.71–2.06 Å. Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two VO6 octahedra, corners with four PO4 tetrahedra, and edges with two equivalent NiO6 octahedra. The corner-sharing octahedra tilt angles range from 48–49°. There are a spread of Ni–O bond distances ranging from 1.97–2.15 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 two equivalent NiO6 octahedra and corners with three VO6 octahedra. The corner-sharing octahedra tilt angles range from 7–54°. There are a spread of P–O bond distances ranging from 1.52–1.56 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent NiO6 octahedra and corners with three VO6 octahedra. The corner-sharing octahedra tilt angles range from 6–52°. There are a spread of P–O bond distances ranging from 1.53–1.56 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent NiO6 octahedra and an edgeedge with one VO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of P–O bond distances ranging from 1.53–1.59 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent NiO6 octahedra and an edgeedge with one VO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of P–O bond distances ranging from 1.51–1.62 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to one Ni2+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one 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 two equivalent Ni2+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to one V5+ and two equivalent Ni2+ atoms. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to one V5+ and two equivalent Ni2+ atoms. In the seventh O2- site, O2- is bonded in an L-shaped geometry to one V5+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+, one V5+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one V5+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to one V5+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in an L-shaped geometry to one V5+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one V5+, and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a linear geometry to one V5+ and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a linear geometry to one V5+ and one P5+ atom.