Materials Data on CaCuSiH2O5 by Materials Project
CaCuSiH2O5 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.35–2.51 Å. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded in a square co-planar geometry to four O2- atoms. There is two shorter (1.93 Å) and two longer (2.00 Å) Cu–O bond length. In the second Cu2+ site, Cu2+ is bonded in a square co-planar geometry to four O2- atoms. There is two shorter (1.96 Å) and two longer (1.98 Å) Cu–O bond length. Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Si–O bond distances ranging from 1.64–1.68 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.04 Å) and one longer (1.57 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 0.99 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+, one Si4+, and one H1+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Cu2+, and one Si4+ atom. In the third O2- site, O2- is bonded to one Ca2+, two Cu2+, and one Si4+ atom to form distorted corner-sharing OCaCu2Si trigonal pyramids. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Cu2+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to two equivalent Ca2+ and two H1+ atoms.