Materials Data on Ba3Na(SiO4)2 by Materials Project

Abstract

NaBa3(SiO4)2 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Na is bonded to six O atoms to form NaO6 octahedra that share corners with six equivalent SiO4 tetrahedra. There are two shorter (2.39 Å) and four longer (2.40 Å) Na–O bond lengths. There are two inequivalent Ba sites. In the first Ba site, Ba is bonded in a 12-coordinate geometry to seven O atoms. There are a spread of Ba–O bond distances ranging from 2.84–2.95 Å. In the second Ba site, Ba is bonded in a 1-coordinate geometry to ten O atoms. There are a spread of Ba–O bond distances ranging from 2.62–3.16 Å. Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three equivalent NaO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 20–23°. There is three shorter (1.64 Å) and one longer (1.66 Å) Si–O bond length. There are four inequivalent O sites. In the first O site, O is bonded in a linear geometry to two equivalent Si atoms. In the second O site, O is bonded in a distorted T-shaped geometry to three Ba atoms. In the third O site, O is bonded in a 1-coordinate geometry to one Na, four Ba, and one Si atom. In the fourth O site, O is bonded in a 1-coordinate geometry to one Na, four Ba, and one Si atom.