Materials Data on NaBeSi3O8 by Materials Project

Abstract

(Na2Be2Si6O15)2O2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional and consists of four water molecules and one Na2Be2Si6O15 framework. In the Na2Be2Si6O15 framework, there are two inequivalent Na sites. In the first Na site, Na is bonded in a distorted rectangular see-saw-like geometry to four O atoms. There are two shorter (2.26 Å) and two longer (2.56 Å) Na–O bond lengths. In the second Na site, Na is bonded to six O atoms to form NaO6 octahedra that share corners with two equivalent SiO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.32–2.59 Å. Be is bonded in a trigonal planar geometry to three O atoms. There are a spread of Be–O bond distances ranging from 1.52–1.55 Å. There are three inequivalent Si sites. In the first Si site, Si is bonded in a trigonal planar geometry to three O atoms. There are a spread of Si–O bond distances ranging from 1.56–1.60 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one NaO6 octahedra. The corner-sharing octahedral tilt angles are 54°. There are a spread of Si–O bond distances ranging from 1.60–1.69 Å. In the third Si site, Si is bonded in a distorted bent 120 degrees geometry to two O atoms. There is one shorter (1.54 Å) and one longer (1.61 Å) Si–O bond length. There are eight inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the second O site, O is bonded in a linear geometry to two equivalent Be atoms. In the third O site, O is bonded in a distorted bent 150 degrees geometry to one Na, one Be, and one Si atom. In the fourth O site, O is bonded in a distorted bent 150 degrees geometry to one Na and one Si atom. In the fifth O site, O is bonded in a bent 120 degrees geometry to one Na and one Si atom. In the sixth O site, O is bonded in a bent 150 degrees geometry to one Be and one Si atom. In the seventh O site, O is bonded in a 1-coordinate geometry to two Na and one Si atom. In the eighth O site, O is bonded in a bent 120 degrees geometry to two Si atoms.