DOI: 10.17188/1277663
title: Materials Data on Mg2PO4F by Materials Project

description: Mg2F(PO4) crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are eight inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to four O2- and two F1- atoms to form distorted MgO4F2 octahedra that share corners with four PO4 tetrahedra, corners with two MgO4F trigonal bipyramids, and edges with three MgO4F2 octahedra. There are a spread of Mg–O bond distances ranging from 2.07–2.18 Å. There are one shorter (2.02 Å) and one longer (2.26 Å) Mg–F bond lengths. In the second Mg2+ site, Mg2+ is bonded to four O2- and one F1- atom to form MgO4F trigonal bipyramids that share corners with two MgO4F2 octahedra, corners with four PO4 tetrahedra, corners with two MgO4F trigonal bipyramids, and an edgeedge with one MgO4F trigonal bipyramid. The corner-sharing octahedra tilt angles range from 49–51°. There are a spread of Mg–O bond distances ranging from 2.04–2.11 Å. The Mg–F bond length is 1.97 Å. In the third Mg2+ site, Mg2+ is bonded to four O2- and two F1- atoms to form distorted MgO4F2 octahedra that share corners with four PO4 tetrahedra, corners with two MgO4F trigonal bipyramids, and edges with three MgO4F2 octahedra. There are three shorter (2.10 Å) and one longer (2.15 Å) Mg–O bond lengths. There are one shorter (2.02 Å) and one longer (2.22 Å) Mg–F bond lengths. In the fourth Mg2+ site, Mg2+ is bonded to four O2- and one F1- atom to form distorted MgO4F trigonal bipyramids that share corners with two MgO4F2 octahedra, corners with four PO4 tetrahedra, corners with two MgO4F trigonal bipyramids, and an edgeedge with one MgO4F trigonal bipyramid. The corner-sharing octahedra tilt angles range from 47–52°. There are a spread of Mg–O bond distances ranging from 2.06–2.10 Å. The Mg–F bond length is 1.97 Å. In the fifth Mg2+ site, Mg2+ is bonded to four O2- and two F1- atoms to form MgO4F2 octahedra that share corners with four PO4 tetrahedra, corners with two MgO4F trigonal bipyramids, edges with two MgO4F2 octahedra, and an edgeedge with one MgO4F trigonal bipyramid. There are a spread of Mg–O bond distances ranging from 2.06–2.12 Å. There are one shorter (2.06 Å) and one longer (2.09 Å) Mg–F bond lengths. In the sixth Mg2+ site, Mg2+ is bonded to four O2- and one F1- atom to form MgO4F trigonal bipyramids that share corners with two MgO4F2 octahedra, corners with four PO4 tetrahedra, corners with two MgO4F trigonal bipyramids, and an edgeedge with one MgO4F2 octahedra. The corner-sharing octahedra tilt angles range from 46–55°. There are a spread of Mg–O bond distances ranging from 2.02–2.09 Å. The Mg–F bond length is 1.98 Å. In the seventh Mg2+ site, Mg2+ is bonded to four O2- and one F1- atom to form MgO4F trigonal bipyramids that share corners with two MgO4F2 octahedra, corners with four PO4 tetrahedra, corners with two MgO4F trigonal bipyramids, and an edgeedge with one MgO4F trigonal bipyramid. The corner-sharing octahedra tilt angles range from 46–55°. There are a spread of Mg–O bond distances ranging from 2.03–2.05 Å. The Mg–F bond length is 1.97 Å. In the eighth Mg2+ site, Mg2+ is bonded to four O2- and two F1- atoms to form MgO4F2 octahedra that share corners with four PO4 tetrahedra, corners with two MgO4F trigonal bipyramids, and edges with three MgO4F2 octahedra. There are a spread of Mg–O bond distances ranging from 2.08–2.16 Å. There are one shorter (2.06 Å) and one longer (2.10 Å) Mg–F bond lengths. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with six MgO4F2 octahedra and corners with two MgO4F trigonal bipyramids. The corner-sharing octahedra tilt angles range from 45–58°. There is two shorter (1.55 Å) and two longer (1.56 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two MgO4F2 octahedra and corners with six MgO4F trigonal bipyramids. The corner-sharing octahedra tilt angles range from 44–60°. There is one shorter (1.54 Å) and three longer (1.55 Å) P–O bond length. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three MgO4F2 octahedra and corners with five MgO4F trigonal bipyramids. The corner-sharing octahedra tilt angles range from 51–53°. There is one shorter (1.54 Å) and three longer (1.56 Å) P–O bond length. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with five MgO4F2 octahedra and corners with three MgO4F trigonal bipyramids. The corner-sharing octahedra tilt angles range from 43–59°. There is three shorter (1.55 Å) and one longer (1.56 Å) P–O bond length. There are sixteen 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 3-coordinate geometry to two Mg2+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two 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. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two Mg2+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two 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 trigonal planar geometry to two Mg2+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one P5+ atom. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal planar geometry to three Mg2+ atoms. In the second F1- site, F1- is bonded in a 3-coordinate geometry to three Mg2+ atoms. In the third F1- site, F1- is bonded in a 3-coordinate geometry to three Mg2+ atoms. In the fourth F1- site, F1- is bonded in a distorted trigonal planar geometry to three Mg2+ atoms.