Materials Data on KVNiOF6 by Materials Project
KVNiOF6 crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. K1+ is bonded to two equivalent O2- and six F1- atoms to form KO2F6 hexagonal bipyramids that share edges with two equivalent KO2F6 hexagonal bipyramids, edges with two equivalent VF6 octahedra, and edges with four equivalent NiF6 octahedra. Both K–O bond lengths are 2.62 Å. There are two shorter (2.71 Å) and four longer (2.74 Å) K–F bond lengths. V5+ is bonded to six F1- atoms to form VF6 octahedra that share corners with two equivalent VF6 octahedra, corners with four equivalent NiF6 octahedra, and edges with two equivalent KO2F6 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 35–39°. There is four shorter (1.95 Å) and two longer (2.00 Å) V–F bond length. Ni2+ is bonded to six F1- atoms to form NiF6 octahedra that share corners with two equivalent NiF6 octahedra, corners with four equivalent VF6 octahedra, and edges with four equivalent KO2F6 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 39–42°. There are two shorter (2.03 Å) and four longer (2.06 Å) Ni–F bond lengths. O2- is bonded in a distorted L-shaped geometry to two equivalent K1+ and one F1- atom. The O–F bond length is 2.90 Å. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a 4-coordinate geometry to two equivalent K1+ and two equivalent Ni2+ atoms. In the second F1- site, F1- is bonded in a bent 150 degrees geometry to two equivalent V5+ and one O2- atom. In the third F1- site, F1- is bonded in a 2-coordinate geometry to one K1+, one V5+, and one Ni2+ atom.