Materials Data on CaSiO3 by Materials Project

Abstract

CaSiO3 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to eight O2- atoms to form distorted CaO8 hexagonal bipyramids that share corners with two equivalent CaO8 hexagonal bipyramids, corners with two equivalent SiO4 tetrahedra, edges with six equivalent CaO8 hexagonal bipyramids, and edges with four SiO4 tetrahedra. There are a spread of Ca–O bond distances ranging from 2.32–2.68 Å. In the second Ca2+ site, Ca2+ is bonded to eight O2- atoms to form distorted CaO8 hexagonal bipyramids that share corners with two CaO8 hexagonal bipyramids, corners with two SiO4 tetrahedra, edges with six CaO8 hexagonal bipyramids, and edges with four SiO4 tetrahedra. There are a spread of Ca–O bond distances ranging from 2.29–2.67 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent CaO8 hexagonal bipyramids, corners with two equivalent SiO4 tetrahedra, and edges with four CaO8 hexagonal bipyramids. There is two shorter (1.60 Å) and two longer (1.68 Å) Si–O bond length. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two CaO8 hexagonal bipyramids, corners with two SiO4 tetrahedra, and edges with four CaO8 hexagonal bipyramids. There are a spread of Si–O bond distances ranging from 1.60–1.68 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Si4+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two equivalent Si4+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+ and two Si4+ atoms.