Materials Data on Na2Mg2Fe2Se3(SO8)3 by Materials Project

Abstract

Na2Mg2Fe2Se3(SO8)3 crystallizes in the trigonal R3 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a hexagonal planar geometry to six O2- atoms. There are three shorter (2.50 Å) and three longer (2.58 Å) Na–O bond lengths. In the second Na1+ site, Na1+ is bonded in a distorted hexagonal planar geometry to six O2- atoms. There are three shorter (2.50 Å) and three longer (2.60 Å) Na–O bond lengths. There are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with three equivalent SeO4 tetrahedra and corners with three equivalent SO4 tetrahedra. There are three shorter (2.06 Å) and three longer (2.12 Å) Mg–O bond lengths. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with three equivalent SeO4 tetrahedra and corners with three equivalent SO4 tetrahedra. There are three shorter (2.06 Å) and three longer (2.11 Å) Mg–O bond lengths. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three equivalent SeO4 tetrahedra and corners with three equivalent SO4 tetrahedra. There are three shorter (2.01 Å) and three longer (2.06 Å) Fe–O bond lengths. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three equivalent SeO4 tetrahedra and corners with three equivalent SO4 tetrahedra. There are three shorter (1.97 Å) and three longer (2.06 Å) Fe–O bond lengths. Se6+ is bonded to four O2- atoms to form SeO4 tetrahedra that share corners with two MgO6 octahedra and corners with two FeO6 octahedra. The corner-sharing octahedra tilt angles range from 30–44°. There is two shorter (1.65 Å) and two longer (1.68 Å) Se–O bond length. S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with two MgO6 octahedra and corners with two FeO6 octahedra. The corner-sharing octahedra tilt angles range from 28–37°. There are a spread of S–O bond distances ranging from 1.47–1.50 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe3+ and one S6+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe3+ and one Se6+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Mg2+ and one Se6+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Mg2+ and one S6+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Fe3+, and one Se6+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Fe3+, and one S6+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Mg2+, and one S6+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Mg2+, and one Se6+ atom.