Materials Data on KNiPH2O5 by Materials Project
KNiPH2O5 crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. K1+ is bonded in a 5-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.69–3.17 Å. Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four equivalent NiO6 octahedra, corners with three equivalent PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 60°. There are a spread of Ni–O bond distances ranging from 2.05–2.17 Å. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent NiO6 octahedra and an edgeedge with one NiO6 octahedra. The corner-sharing octahedra tilt angles range from 45–56°. There are a spread of P–O bond distances ranging from 1.53–1.59 Å. H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Ni2+, and one P5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to four equivalent K1+ and one P5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, two equivalent Ni2+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to one K1+, one Ni2+, and two equivalent H1+ atoms.