Materials Data on MgZn2(PO4)2 by Materials Project
MgZn2(PO4)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six equivalent PO4 tetrahedra, corners with two equivalent ZnO5 trigonal bipyramids, and edges with two equivalent ZnO5 trigonal bipyramids. There are two shorter (2.00 Å) and four longer (2.21 Å) Mg–O bond lengths. Zn2+ is bonded to five O2- atoms to form distorted ZnO5 trigonal bipyramids that share a cornercorner with one MgO6 octahedra, corners with three equivalent PO4 tetrahedra, an edgeedge with one MgO6 octahedra, an edgeedge with one PO4 tetrahedra, and an edgeedge with one ZnO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 61°. There are a spread of Zn–O bond distances ranging from 1.98–2.37 Å. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent MgO6 octahedra, corners with three equivalent ZnO5 trigonal bipyramids, and an edgeedge with one ZnO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 29–54°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+, one Zn2+, and one P5+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+, one Zn2+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Zn2+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Zn2+, and one P5+ atom.