Materials Data on Cs2SiB4O9 by Materials Project

Abstract

Cs2B4SiO9 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Cs–O bond distances ranging from 3.18–3.32 Å. In the second Cs1+ site, Cs1+ is bonded in a 2-coordinate geometry to ten O2- atoms. There are a spread of Cs–O bond distances ranging from 3.13–3.65 Å. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded to four O2- atoms to form BO4 tetrahedra that share a cornercorner with one BO4 tetrahedra and a cornercorner with one SiO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.45–1.53 Å. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.37 Å) and one longer (1.39 Å) B–O bond length. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent BO4 tetrahedra. There is two shorter (1.63 Å) and two longer (1.66 Å) Si–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Cs1+, one B3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Cs1+, one B3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to two Cs1+ and two B3+ atoms. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two Cs1+ and two B3+ atoms. In the fifth O2- site, O2- is bonded in a water-like geometry to three Cs1+ and two equivalent B3+ atoms.