DOI: 10.17188/1270044
title: Materials Data on KMg4(PO4)3 by Materials Project

description: KMg4(PO4)3 crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. K1+ is bonded in a 6-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.79–3.18 Å. There are three inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share a cornercorner with one MgO6 octahedra, corners with four PO4 tetrahedra, a cornercorner with one MgO5 trigonal bipyramid, edges with three MgO6 octahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 68°. There are a spread of Mg–O bond distances ranging from 2.04–2.43 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with four PO4 tetrahedra, edges with two equivalent MgO6 octahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 68°. There are a spread of Mg–O bond distances ranging from 1.96–2.33 Å. In the third Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share corners with two equivalent MgO6 octahedra, corners with five PO4 tetrahedra, and an edgeedge with one MgO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 60°. There are a spread of Mg–O bond distances ranging from 1.99–2.15 Å. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four MgO6 octahedra, a cornercorner with one MgO5 trigonal bipyramid, and edges with two equivalent MgO6 octahedra. The corner-sharing octahedra tilt angles range from 43–52°. There are a spread of P–O bond distances ranging from 1.54–1.59 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three MgO6 octahedra, corners with two equivalent MgO5 trigonal bipyramids, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 9–58°. There are a spread of P–O bond distances ranging from 1.52–1.57 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with five MgO6 octahedra and corners with two equivalent MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 49–63°. There are a spread of P–O bond distances ranging from 1.53–1.61 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mg2+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+, one Mg2+, and one P5+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, two Mg2+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, two Mg2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Mg2+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mg2+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted tetrahedral geometry to three Mg2+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mg2+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted linear geometry to two equivalent K1+, one Mg2+, and one P5+ atom.