Materials Data on Be4Si2O9 by Materials Project
Be4Si2O9 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are two inequivalent Be sites. In the first Be site, Be is bonded to four O atoms to form BeO4 tetrahedra that share corners with two SiO4 tetrahedra and corners with four BeO4 tetrahedra. There are a spread of Be–O bond distances ranging from 1.60–1.67 Å. In the second Be site, Be is bonded to four O atoms to form BeO4 tetrahedra that share corners with four BeO4 tetrahedra and corners with four SiO4 tetrahedra. There are a spread of Be–O bond distances ranging from 1.65–1.71 Å. There are two inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent SiO4 tetrahedra and corners with four BeO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.65 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with eight BeO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.64–1.67 Å. There are six inequivalent O sites. In the first O site, O is bonded in a trigonal non-coplanar geometry to two equivalent Be and one Si atom. In the second O site, O is bonded in a bent 120 degrees geometry to two equivalent Be atoms. In the third O site, O is bonded in a bent 120 degrees geometry to two equivalent Si atoms. In the fourth O site, O is bonded in a trigonal planar geometry to two equivalent Be and one Si atom. In the fifth O site, O is bonded in a trigonal non-coplanar geometry to two equivalent Be and one Si atom. In the sixth O site, O is bonded in a trigonal planar geometry to two Be and one Si atom.