Materials Data on Na2MgPO4F by Materials Project

Abstract

Na2Mg(PO4)F crystallizes in the orthorhombic Pbcn space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 7-coordinate geometry to five O2- and two F1- atoms. There are a spread of Na–O bond distances ranging from 2.39–2.98 Å. There are one shorter (2.39 Å) and one longer (2.70 Å) Na–F bond lengths. In the second Na1+ site, Na1+ is bonded in a 7-coordinate geometry to five O2- and two F1- atoms. There are a spread of Na–O bond distances ranging from 2.30–2.80 Å. There are one shorter (2.38 Å) and one longer (2.46 Å) Na–F bond lengths. Mg2+ is bonded to four O2- and two F1- atoms to form distorted MgO4F2 octahedra that share a cornercorner with one MgO4F2 octahedra, corners with four equivalent PO4 tetrahedra, and a faceface with one MgO4F2 octahedra. The corner-sharing octahedral tilt angles are 63°. There are a spread of Mg–O bond distances ranging from 2.06–2.17 Å. There are one shorter (2.00 Å) and one longer (2.11 Å) Mg–F bond lengths. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four equivalent MgO4F2 octahedra. The corner-sharing octahedra tilt angles range from 36–54°. 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 2-coordinate geometry to three Na1+, one Mg2+, and one P5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to four Na1+ and one P5+ atom. In the third O2- site, O2- is bonded to two Na1+, one Mg2+, and one P5+ atom to form distorted ONa2MgP tetrahedra that share corners with three equivalent FNa4Mg2 octahedra. The corner-sharing octahedra tilt angles range from 4–58°. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Na1+, two equivalent Mg2+, and one P5+ atom. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded to four Na1+ and two equivalent Mg2+ atoms to form FNa4Mg2 octahedra that share corners with six equivalent ONa2MgP tetrahedra. In the second F1- site, F1- is bonded in a 2-coordinate geometry to four Na1+ and two equivalent Mg2+ atoms.