Materials Data on K4NiP6O25 by Materials Project
K4P6O19NiO6 crystallizes in the orthorhombic Fmm2 space group. The structure is three-dimensional and consists of four NiO6 clusters and one K4P6O19 framework. In each NiO6 cluster, Ni is bonded in an octahedral geometry to six O atoms. There is two shorter (1.82 Å) and four longer (1.84 Å) Ni–O bond length. There are three inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Ni atom. In the second O site, O is bonded in a single-bond geometry to one Ni atom. In the third O site, O is bonded in a single-bond geometry to one Ni atom. In the K4P6O19 framework, there are two inequivalent K sites. In the first K site, K is bonded to six O atoms to form distorted KO6 octahedra that share corners with six PO4 tetrahedra and edges with four KO6 octahedra. There are a spread of K–O bond distances ranging from 2.66–2.83 Å. In the second K site, K is bonded to six O atoms to form distorted KO6 octahedra that share a cornercorner with one KO6 octahedra, corners with five PO4 tetrahedra, and edges with two equivalent KO6 octahedra. The corner-sharing octahedral tilt angles are 61°. There are a spread of K–O bond distances ranging from 2.66–3.12 Å. There are two inequivalent P sites. In the first P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with five KO6 octahedra and corners with two equivalent PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 37–59°. There is two shorter (1.49 Å) and two longer (1.65 Å) P–O bond length. In the second P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with three KO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–66°. There are a spread of P–O bond distances ranging from 1.50–1.63 Å. There are seven inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to two equivalent K atoms. In the second O site, O is bonded in a bent 120 degrees geometry to two P atoms. In the third O site, O is bonded in a distorted bent 150 degrees geometry to two equivalent P atoms. In the fourth O site, O is bonded in a distorted single-bond geometry to three K and one P atom. In the fifth O site, O is bonded in a distorted single-bond geometry to two equivalent K and one P atom. In the sixth O site, O is bonded in a distorted bent 120 degrees geometry to one K and one P atom. In the seventh O site, O is bonded in a distorted single-bond geometry to two K and one P atom.