Materials Data on MgPO4 by Materials Project
MgPO4 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent Mg sites. In the first Mg site, Mg is bonded to four O atoms to form MgO4 tetrahedra that share corners with two equivalent MgO6 octahedra and corners with four equivalent PO4 tetrahedra. The corner-sharing octahedral tilt angles are 61°. There are two shorter (1.95 Å) and two longer (2.05 Å) Mg–O bond lengths. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six PO4 tetrahedra and edges with two equivalent MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.03–2.21 Å. In the third Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share a cornercorner with one MgO4 tetrahedra, corners with five PO4 tetrahedra, and edges with two MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.03–2.18 Å. There are two inequivalent P sites. In the first P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with five MgO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 39–60°. There are a spread of P–O bond distances ranging from 1.52–1.63 Å. In the second P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with three MgO6 octahedra, a cornercorner with one PO4 tetrahedra, and corners with two equivalent MgO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–64°. There are a spread of P–O bond distances ranging from 1.51–1.62 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to two P atoms. In the second O site, O is bonded in a distorted trigonal planar geometry to two Mg and one P atom. In the third O site, O is bonded in a bent 120 degrees geometry to one Mg and one P atom. In the fourth O site, O is bonded in a distorted trigonal planar geometry to two equivalent Mg and one P atom. In the fifth O site, O is bonded in a trigonal planar geometry to two Mg and one P atom. In the sixth O site, O is bonded in a distorted trigonal planar geometry to two Mg and one P atom. In the seventh O site, O is bonded in a distorted bent 120 degrees geometry to one Mg and one P atom. In the eighth O site, O is bonded in a single-bond geometry to one Mg atom.