DOI: 10.17188/1757818
title: Materials Data on Ca4Si3H2O11 by Materials Project

description: Ca4Si3H2O11 crystallizes in the orthorhombic Ama2 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 a cornercorner with one CaO6 octahedra, corners with five SiO4 tetrahedra, and edges with two CaO6 octahedra. The corner-sharing octahedral tilt angles are 46°. There are a spread of Ca–O bond distances ranging from 2.34–2.44 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share a cornercorner with one CaO6 octahedra, corners with five SiO4 tetrahedra, and edges with two CaO6 octahedra. The corner-sharing octahedral tilt angles are 29°. There are a spread of Ca–O bond distances ranging from 2.28–2.43 Å. In the third Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.35–2.84 Å. In the fourth 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 2.37–2.91 Å. In the fifth Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.38–2.99 Å. In the sixth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six SiO4 tetrahedra and edges with four CaO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.31–2.53 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 four CaO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 40–62°. There are a spread of Si–O bond distances ranging from 1.63–1.69 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four CaO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 46–69°. There are a spread of Si–O bond distances ranging from 1.61–1.70 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with five CaO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–66°. There are a spread of Si–O bond distances ranging from 1.62–1.70 Å. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.03 Å) and one longer (1.63 Å) H–O bond length. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 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 distorted trigonal planar geometry to two Ca2+ and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and two Si4+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Si4+ atom. 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 to three Ca2+ and one Si4+ atom to form distorted edge-sharing OCa3Si trigonal pyramids. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Si4+, and one H1+ atom. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+, one Si4+, and one H1+ atom. In the eleventh O2- site, O2- is bonded in a distorted single-bond geometry to three Ca2+ and one H1+ atom. In the twelfth O2- site, O2- is bonded in a distorted single-bond geometry to four Ca2+ and one H1+ atom.