Materials Data on Ca2Cu2Si3(HO3)4 by Materials Project

Abstract

Ca2Cu2Si3(HO3)4 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.26–2.89 Å. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to five O2- atoms to form distorted CuO5 square pyramids that share corners with three SiO4 tetrahedra and edges with two equivalent CuO5 trigonal bipyramids. There are a spread of Cu–O bond distances ranging from 1.94–2.59 Å. In the second Cu2+ site, Cu2+ is bonded to five O2- atoms to form distorted CuO5 trigonal bipyramids that share corners with three SiO4 tetrahedra and edges with two equivalent CuO5 square pyramids. There are four shorter (1.95 Å) and one longer (2.57 Å) Cu–O bond lengths. There are two 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 CuO5 square pyramid, a cornercorner with one SiO4 tetrahedra, and a cornercorner with one CuO5 trigonal bipyramid. There are a spread of Si–O bond distances ranging from 1.60–1.72 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CuO5 square pyramid, corners with two equivalent SiO4 tetrahedra, and a cornercorner with one CuO5 trigonal bipyramid. There are a spread of Si–O bond distances ranging from 1.61–1.65 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 single-bond geometry to one O2- atom. The H–O bond length is 1.01 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+, one Cu2+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted water-like geometry to two equivalent Ca2+, one Si4+, and one H1+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ca2+ and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to one Ca2+, two Cu2+, and one H1+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Ca2+, one Cu2+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the seventh O2- site, O2- is bonded in a distorted T-shaped geometry to two Cu2+ and one Si4+ atom.