Materials Data on BaBe2Si2O7 by Materials Project
BaBe2Si2O7 crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.80–3.18 Å. Be2+ is bonded to four O2- atoms to form BeO4 tetrahedra that share corners with two equivalent BeO4 tetrahedra and corners with four equivalent SiO4 tetrahedra. There are a spread of Be–O bond distances ranging from 1.61–1.69 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with four equivalent BeO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.63–1.68 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ba2+ and two equivalent Si4+ atoms. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Ba2+, one Be2+, and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+, one Be2+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Be2+ and one Si4+ atom.