Materials Data on Ni5(AsO6)2 by Materials Project
Ni5(AsO6)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Ni+2.80+ sites. In the first Ni+2.80+ site, Ni+2.80+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four equivalent AsO4 tetrahedra and edges with five NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.93–2.09 Å. In the second Ni+2.80+ site, Ni+2.80+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four equivalent AsO4 tetrahedra and edges with four NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.91–2.16 Å. In the third Ni+2.80+ site, Ni+2.80+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two equivalent AsO4 tetrahedra and edges with six NiO6 octahedra. There are four shorter (1.89 Å) and two longer (2.21 Å) Ni–O bond lengths. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with nine NiO6 octahedra. The corner-sharing octahedra tilt angles range from 54–56°. There are a spread of As–O bond distances ranging from 1.72–1.76 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two Ni+2.80+ and one As5+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Ni+2.80+ and one As5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ni+2.80+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Ni+2.80+ atoms.