DOI: 10.17188/1322910
title: Materials Data on MgVNiP2O9 by Materials Project

description: MgVNiP2O9 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with two NiO6 octahedra, corners with four VO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–66°. There are a spread of Mg–O bond distances ranging from 2.19–2.56 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with two NiO6 octahedra, corners with four VO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–66°. There are a spread of Mg–O bond distances ranging from 2.19–2.54 Å. There are two inequivalent V4+ sites. In the first V4+ site, V4+ is bonded to six O2- atoms to form distorted VO6 octahedra that share corners with two NiO6 octahedra, corners with four MgO6 octahedra, corners with three equivalent PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–66°. There are a spread of V–O bond distances ranging from 1.71–2.11 Å. In the second V4+ site, V4+ is bonded to six O2- atoms to form distorted VO6 octahedra that share corners with two NiO6 octahedra, corners with four MgO6 octahedra, corners with three equivalent PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–66°. There are a spread of V–O bond distances ranging from 1.71–2.12 Å. There are four inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with two equivalent VO6 octahedra, corners with four PO4 tetrahedra, and edges with two equivalent NiO6 octahedra. The corner-sharing octahedra tilt angles range from 50–66°. There are a spread of Ni–O bond distances ranging from 2.01–2.14 Å. In the second Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with two equivalent VO6 octahedra, corners with four PO4 tetrahedra, and edges with two equivalent NiO6 octahedra. The corner-sharing octahedra tilt angles range from 50–66°. There are a spread of Ni–O bond distances ranging from 2.01–2.14 Å. In the third Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with two equivalent VO6 octahedra, corners with four PO4 tetrahedra, and edges with two equivalent NiO6 octahedra. The corner-sharing octahedra tilt angles range from 50–65°. There are a spread of Ni–O bond distances ranging from 2.01–2.14 Å. In the fourth Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with two equivalent VO6 octahedra, corners with four PO4 tetrahedra, and edges with two equivalent NiO6 octahedra. The corner-sharing octahedra tilt angles range from 51–66°. There are a spread of Ni–O bond distances ranging from 2.01–2.14 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 NiO6 octahedra, corners with three equivalent VO6 octahedra, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 7–53°. There are a spread of P–O bond distances ranging from 1.51–1.55 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two NiO6 octahedra, corners with three equivalent VO6 octahedra, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 7–52°. There are a spread of P–O bond distances ranging from 1.51–1.55 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two NiO6 octahedra, corners with four MgO6 octahedra, and an edgeedge with one VO6 octahedra. The corner-sharing octahedra tilt angles range from 27–65°. There is two shorter (1.55 Å) and two longer (1.57 Å) P–O bond length. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two NiO6 octahedra, corners with four MgO6 octahedra, and an edgeedge with one VO6 octahedra. The corner-sharing octahedra tilt angles range from 27–65°. There is two shorter (1.55 Å) and two longer (1.57 Å) P–O bond length. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+, one Ni2+, and one P5+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+, one Ni2+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+, one Ni2+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+, one Ni2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ni2+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ni2+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one V4+ and two Ni2+ atoms. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one V4+ and two Ni2+ atoms. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one V4+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one V4+, and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one V4+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one V4+, and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one V4+, and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one V4+, and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Mg2+, one V4+, and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Mg2+, one V4+, and one P5+ atom. In the seventeenth O2- site, O2- is bonded in a linear geometry to one V4+ and one P5+ atom. In the eighteenth O2- site, O2- is bonded in a linear geometry to one V4+ and one P5+ atom.