Materials Data on Rb2Ca2(SiO3)3 by Materials Project
Rb2Ca2(SiO3)3 crystallizes in the monoclinic Pc space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Rb–O bond distances ranging from 2.82–2.87 Å. In the second Rb1+ site, Rb1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Rb–O bond distances ranging from 2.91–3.43 Å. There are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to five O2- atoms to form distorted CaO5 trigonal bipyramids that share corners with five SiO4 tetrahedra and edges with two equivalent CaO5 trigonal bipyramids. There are a spread of Ca–O bond distances ranging from 2.29–2.36 Å. In the second Ca2+ site, Ca2+ is bonded to five O2- atoms to form distorted CaO5 trigonal bipyramids that share corners with five SiO4 tetrahedra and edges with two equivalent CaO5 trigonal bipyramids. There are a spread of Ca–O bond distances ranging from 2.22–2.39 Å. There are three inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two SiO4 tetrahedra and corners with two CaO5 trigonal bipyramids. There are a spread of Si–O bond distances ranging from 1.62–1.69 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two SiO4 tetrahedra and corners with four CaO5 trigonal bipyramids. There are a spread of Si–O bond distances ranging from 1.61–1.69 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two SiO4 tetrahedra and corners with four CaO5 trigonal bipyramids. There are a spread of Si–O bond distances ranging from 1.62–1.69 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two Ca2+ and one Si4+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two Rb1+ and two Si4+ atoms. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Rb1+, one Ca2+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Rb1+, two Ca2+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two Ca2+ and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two Rb1+, one Ca2+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to one Rb1+, two Ca2+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to one Rb1+ and two Si4+ atoms. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Si4+ atoms.