DOI: 10.17188/1752407
title: Materials Data on K4Ni7(AsO4)6 by Materials Project

description: K4Ni7(AsO4)6 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.64–3.20 Å. In the second K1+ site, K1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.65–3.24 Å. In the third K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 2.64–2.77 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 four NiO6 octahedra and corners with six AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–53°. There are a spread of Ni–O bond distances ranging from 2.08–2.12 Å. In the second Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with three NiO6 octahedra, corners with four AsO4 tetrahedra, an edgeedge with one NiO6 octahedra, and an edgeedge with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–61°. There are a spread of Ni–O bond distances ranging from 2.05–2.15 Å. In the third Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with three NiO6 octahedra, corners with four AsO4 tetrahedra, an edgeedge with one NiO6 octahedra, and an edgeedge with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–60°. There are a spread of Ni–O bond distances ranging from 2.06–2.20 Å. In the fourth Ni2+ site, Ni2+ is bonded to six O2- atoms to form distorted NiO6 octahedra that share corners with four NiO6 octahedra, corners with two AsO4 tetrahedra, an edgeedge with one NiO6 octahedra, and edges with two AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–61°. There are a spread of Ni–O bond distances ranging from 2.08–2.36 Å. There are four inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with three NiO6 octahedra and edges with two equivalent NiO6 octahedra. The corner-sharing octahedra tilt angles range from 54–59°. There is one shorter (1.69 Å) and three longer (1.74 Å) As–O bond length. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with three NiO6 octahedra and edges with two equivalent NiO6 octahedra. The corner-sharing octahedra tilt angles range from 57–59°. There are a spread of As–O bond distances ranging from 1.70–1.75 Å. In the third As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with five NiO6 octahedra and an edgeedge with one NiO6 octahedra. The corner-sharing octahedra tilt angles range from 29–61°. There are a spread of As–O bond distances ranging from 1.70–1.77 Å. In the fourth As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with five NiO6 octahedra and an edgeedge with one NiO6 octahedra. The corner-sharing octahedra tilt angles range from 33–62°. There are a spread of As–O bond distances ranging from 1.70–1.75 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, two Ni2+, and one As5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, two Ni2+, and one As5+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two K1+, one Ni2+, and one As5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one Ni2+, and one As5+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, two Ni2+, and one As5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, two Ni2+, and one As5+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent K1+, one Ni2+, and one As5+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one K1+, one Ni2+, and one As5+ atom. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, two Ni2+, and one As5+ atom. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, two Ni2+, and one As5+ atom. In the eleventh O2- site, O2- is bonded in a 6-coordinate geometry to three K1+, two equivalent Ni2+, and one As5+ atom. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to three K1+, two equivalent Ni2+, and one As5+ atom. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, two Ni2+, and one As5+ atom. In the fourteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ni2+ and one As5+ atom.