Materials Data on K2Mg2(SO4)3 by Materials Project
K2Mg2(SO4)3 crystallizes in the cubic P2_13 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.86–3.21 Å. In the second K1+ site, K1+ is bonded in a 12-coordinate geometry to twelve O2- atoms. There are a spread of K–O bond distances ranging from 2.92–3.25 Å. 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 six equivalent SO4 tetrahedra. All Mg–O bond lengths are 2.10 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six equivalent SO4 tetrahedra. There are three shorter (2.07 Å) and three longer (2.09 Å) Mg–O bond lengths. S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with four MgO6 octahedra. The corner-sharing octahedra tilt angles range from 14–49°. There is one shorter (1.48 Å) and three longer (1.49 Å) S–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to two K1+, one Mg2+, and one S6+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Mg2+, and one S6+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to three K1+, one Mg2+, and one S6+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+, one Mg2+, and one S6+ atom.