Materials Data on Mg2PHO5 by Materials Project

Abstract

Mg2(PO4)OH crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to five O2- atoms to form distorted MgO5 trigonal bipyramids that share corners with two equivalent MgO6 octahedra, corners with four equivalent PO4 tetrahedra, and edges with two equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Mg–O bond distances ranging from 1.94–2.19 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with four equivalent PO4 tetrahedra, corners with two equivalent MgO5 trigonal bipyramids, edges with two equivalent MgO6 octahedra, and edges with two equivalent MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 2.10–2.14 Å. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four equivalent MgO6 octahedra and corners with four equivalent MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 47–57°. There are a spread of P–O bond distances ranging from 1.52–1.58 Å. H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three Mg2+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three Mg2+ and one H1+ atom. In the third O2- site, O2- is bonded in a linear geometry to one Mg2+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one P5+ atom.