DOI: 10.17188/1267758
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 to six O2- atoms to form distorted CaO6 octahedra that share corners with two equivalent CaO6 octahedra, a cornercorner with one CaO6 pentagonal pyramid, corners with four SiO4 tetrahedra, edges with two equivalent CaO6 octahedra, and faces with two equivalent CaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 78°. There are a spread of Ca–O bond distances ranging from 2.32–2.62 Å. In the second 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 2.36–2.71 Å. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 pentagonal pyramids that share a cornercorner with one CaO6 octahedra, corners with two CaO6 pentagonal pyramids, corners with four SiO4 tetrahedra, faces with two CaO6 octahedra, and faces with two CaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 8°. There are a spread of Ca–O bond distances ranging from 2.34–2.54 Å. In the fourth Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 pentagonal pyramids that share a cornercorner with one CaO6 octahedra, corners with two equivalent CaO6 pentagonal pyramids, corners with four SiO4 tetrahedra, faces with two equivalent CaO6 octahedra, and faces with two equivalent CaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 8°. There are a spread of Ca–O bond distances ranging from 2.34–2.53 Å. In the fifth Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with two CaO6 octahedra, a cornercorner with one CaO6 pentagonal pyramid, corners with four SiO4 tetrahedra, edges with two CaO6 octahedra, and faces with two CaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 78°. There are a spread of Ca–O bond distances ranging from 2.32–2.63 Å. In the sixth 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 2.36–2.69 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 three CaO6 octahedra and corners with six CaO6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 55–57°. There is one shorter (1.63 Å) and three longer (1.64 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 three CaO6 octahedra and corners with three CaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 60°. There is three shorter (1.66 Å) and one longer (1.68 Å) Si–O bond length. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with six CaO6 octahedra and corners with three CaO6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 54–56°. There is one shorter (1.63 Å) and three longer (1.64 Å) Si–O bond length. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded to three Ca2+ and one Si4+ atom to form distorted corner-sharing OCa3Si tetrahedra. The corner-sharing octahedra tilt angles range from 11–68°. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Ca2+ and one Si4+ atom. In the third O2- site, O2- is bonded to six Ca2+ atoms to form a mixture of distorted corner and face-sharing OCa6 octahedra. The corner-sharing octahedra tilt angles range from 4–5°. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Ca2+ and one Si4+ atom. In the fifth O2- site, O2- is bonded to six Ca2+ atoms to form OCa6 octahedra that share corners with three equivalent OCa3Si tetrahedra and faces with two OCa6 octahedra. In the sixth O2- site, O2- is bonded to six Ca2+ atoms to form OCa6 octahedra that share corners with three equivalent OCa6 octahedra, corners with three equivalent OCa3Si tetrahedra, and a faceface with one OCa6 octahedra. The corner-sharing octahedra tilt angles range from 4–5°. In the seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Ca2+ and one Si4+ atom. In the eighth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Ca2+ and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one Si4+ atom. In the tenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Ca2+ and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Ca2+ and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one Si4+ atom.