DOI: 10.17188/1664078
title: Materials Data on SrCa3Mg4(SiO3)8 by Materials Project

description: SrCa3Mg4(SiO3)8 is Esseneite-derived structured and crystallizes in the monoclinic P2 space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.47–2.77 Å. There are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.37–2.78 Å. In the second Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.37–2.78 Å. In the third Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.37–2.77 Å. There are four inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.08–2.14 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.08–2.17 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.08–2.15 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.08–2.16 Å. There are four inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 34–59°. There are a spread of Si–O bond distances ranging from 1.60–1.70 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 34–58°. There are a spread of Si–O bond distances ranging from 1.61–1.71 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 31–59°. There are a spread of Si–O bond distances ranging from 1.60–1.71 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 34–58°. There are a spread of Si–O bond distances ranging from 1.61–1.71 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to one Ca2+, one Mg2+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to one Ca2+, one Mg2+, and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted T-shaped geometry to one Sr2+, one Mg2+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted T-shaped geometry to one Ca2+, one Mg2+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two Mg2+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Sr2+, two Mg2+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two Mg2+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two Mg2+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+, one Ca2+, and two Si4+ atoms. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+, one Ca2+, and two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+ and two Si4+ atoms.