Materials Data on Rb2Ca2(SO4)3 by Materials Project
Rb2Ca2(SO4)3 crystallizes in the cubic P2_13 space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Rb–O bond distances ranging from 3.06–3.40 Å. In the second Rb1+ site, Rb1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Rb–O bond distances ranging from 3.09–3.30 Å. There are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six equivalent SO4 tetrahedra. All Ca–O bond lengths are 2.34 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six equivalent SO4 tetrahedra. There are three shorter (2.34 Å) and three longer (2.37 Å) Ca–O bond lengths. S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with four CaO6 octahedra. The corner-sharing octahedra tilt angles range from 15–49°. All S–O bond lengths are 1.49 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Rb1+, one Ca2+, and one S6+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Rb1+, one Ca2+, and one S6+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two Rb1+, one Ca2+, and one S6+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Rb1+, one Ca2+, and one S6+ atom.