DOI: 10.17188/1719372
title: Materials Data on Ca3SiO5 by Materials Project

description: Ca3SiO5 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are six inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.29–2.65 Å. In the second Ca2+ site, Ca2+ is bonded to seven O2- atoms to form distorted CaO7 pentagonal bipyramids that share a cornercorner with one CaO6 octahedra, corners with three SiO4 tetrahedra, an edgeedge with one CaO7 pentagonal bipyramid, an edgeedge with one SiO4 tetrahedra, a faceface with one CaO6 octahedra, and a faceface with one CaO7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 75°. There are a spread of Ca–O bond distances ranging from 2.35–2.65 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 2.39–2.98 Å. In the fourth Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.32–2.72 Å. In the fifth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two equivalent CaO7 pentagonal bipyramids, corners with four SiO4 tetrahedra, and faces with two equivalent CaO7 pentagonal bipyramids. There are a spread of Ca–O bond distances ranging from 2.24–2.45 Å. In the sixth 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 2.31–2.56 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 a cornercorner with one CaO6 octahedra and corners with two equivalent CaO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 65°. There are a spread of Si–O bond distances ranging from 1.64–1.67 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent CaO6 octahedra and corners with four equivalent CaO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 49°. There is two shorter (1.64 Å) and two longer (1.66 Å) Si–O bond length. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CaO6 octahedra and edges with two equivalent CaO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 25°. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Ca2+ and one Si4+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to three Ca2+ and one Si4+ atom. In the third O2- site, O2- is bonded in a 5-coordinate geometry to four Ca2+ and one Si4+ atom. 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 to six Ca2+ atoms to form a mixture of distorted face and corner-sharing OCa6 octahedra. The corner-sharing octahedra tilt angles range from 7–24°. In the sixth O2- site, O2- is bonded to six Ca2+ atoms to form a mixture of face and corner-sharing OCa6 octahedra. The corner-sharing octahedra tilt angles range from 7–24°. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to four Ca2+ and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to four Ca2+ and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Si4+ atom. In the eleventh O2- site, O2- is bonded to six Ca2+ atoms to form face-sharing OCa6 octahedra. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to four Ca2+ and one Si4+ atom.