Materials Data on CuNi2(PO4)2 by Materials Project
CuNi2(PO4)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ni2+ is bonded to five O2- atoms to form NiO5 trigonal bipyramids that share corners with five equivalent PO4 tetrahedra and an edgeedge with one NiO5 trigonal bipyramid. There are a spread of Ni–O bond distances ranging from 2.03–2.08 Å. Cu2+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are two shorter (1.96 Å) and two longer (2.04 Å) Cu–O bond lengths. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with five equivalent NiO5 trigonal bipyramids. There are a spread of P–O bond distances ranging from 1.53–1.57 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to one Ni2+, one Cu2+, and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ni2+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ni2+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ni2+, one Cu2+, and one P5+ atom.