Materials Data on BaSi2(BO4)2 by Materials Project

Abstract

BaB2Si2O8 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.71–3.20 Å. B3+ is bonded to four O2- atoms to form BO4 tetrahedra that share a cornercorner with one BO4 tetrahedra and corners with three equivalent SiO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.47–1.51 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three equivalent BO4 tetrahedra. There is two shorter (1.63 Å) and two longer (1.64 Å) Si–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+ and two equivalent B3+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+, one B3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one B3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ba2+, one B3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Si4+ atoms.