Materials Data on Ca2SiO4 by Materials Project

Abstract

Ca2SiO4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Ca–O bond distances ranging from 2.25–2.67 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six equivalent SiO4 tetrahedra and edges with two equivalent CaO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.41–2.49 Å. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six equivalent SiO4 tetrahedra and edges with two equivalent CaO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.25–2.46 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with six CaO6 octahedra. The corner-sharing octahedra tilt angles range from 30–62°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. There are four 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 distorted trigonal planar geometry to two Ca2+ and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Si4+ atom. In the fourth O2- site, O2- is bonded to three Ca2+ and one Si4+ atom to form distorted corner-sharing OCa3Si tetrahedra.