Materials Data on CaMg2(SO4)3 by Materials Project

Abstract

CaMg2(SO4)3 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. Ca2+ is bonded in a distorted hexagonal planar geometry to six equivalent O2- atoms. All Ca–O bond lengths are 2.43 Å. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six equivalent SO4 tetrahedra and a faceface with one MgO6 octahedra. There are three shorter (2.04 Å) and three longer (2.17 Å) Mg–O bond lengths. S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with four equivalent MgO6 octahedra. The corner-sharing octahedra tilt angles range from 32–49°. There are a spread of S–O bond distances ranging from 1.47–1.50 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Mg2+ and one S6+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ca2+ and one S6+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Mg2+ and one S6+ atom.