Materials Data on Ca2SiH2O5 by Materials Project
Ca2SiO3(OH)2 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. there are two 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 2.28–2.39 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 2.33–2.61 Å. Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Si–O bond distances ranging from 1.63–1.72 Å. There are two inequivalent H1+ sites. In the first 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 second H1+ site, H1+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.02 Å) and one longer (1.64 Å) H–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two 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 distorted single-bond geometry to three Ca2+ and one H1+ atom. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to one Ca2+, one Si4+, and one H1+ atom. In the fifth O2- site, O2- is bonded in a distorted tetrahedral geometry to two Ca2+, one Si4+, and one H1+ atom.