Materials Data on MgSi(OF)6 by Materials Project

Abstract

MgSi(OF)6 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Mg is bonded to four O and two equivalent F atoms to form distorted MgO4F2 octahedra that share corners with two equivalent SiF6 octahedra. The corner-sharing octahedral tilt angles are 34°. There are two shorter (2.26 Å) and two longer (2.33 Å) Mg–O bond lengths. Both Mg–F bond lengths are 1.87 Å. Si is bonded to six F atoms to form SiF6 octahedra that share corners with two equivalent MgO4F2 octahedra. The corner-sharing octahedral tilt angles are 34°. There is four shorter (1.68 Å) and two longer (1.82 Å) Si–F bond length. There are three inequivalent O sites. In the first O site, O is bonded in a water-like geometry to one Mg and one O atom. The O–O bond length is 1.30 Å. In the second O site, O is bonded in a bent 120 degrees geometry to two O atoms. The O–O bond length is 1.26 Å. In the third O site, O is bonded in a bent 150 degrees geometry to one Mg and one O atom. There are three inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one Si atom. In the second F site, F is bonded in a single-bond geometry to one Si atom. In the third F site, F is bonded in a bent 150 degrees geometry to one Mg and one Si atom.