Materials Data on K2Ca3Si3O10 by Materials Project

Abstract

K2Ca3Si3O10 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.74–3.34 Å. There are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six equivalent SiO4 tetrahedra. There are a spread of Ca–O bond distances ranging from 2.37–2.41 Å. In the second 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 2.28–2.80 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent CaO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 12–44°. 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 corner-sharing SiO4 tetrahedra. There is two shorter (1.61 Å) and two longer (1.67 Å) Si–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent K1+, two Ca2+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to three equivalent K1+ and two Si4+ atoms. In the third O2- site, O2- is bonded in a 6-coordinate geometry to two equivalent K1+, three Ca2+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, three Ca2+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent K1+, two equivalent Ca2+, and one Si4+ atom.