Materials Data on Na8Y3(SiO3)12 by Materials Project

Abstract

Na8Y3(SiO3)12 crystallizes in the trigonal R-3c space group. The structure is three-dimensional. there are three inequivalent Na sites. In the first Na site, Na is bonded to six equivalent O atoms to form NaO6 octahedra that share corners with six equivalent SiO4 tetrahedra and faces with two equivalent NaO6 octahedra. All Na–O bond lengths are 2.49 Å. In the second Na site, Na is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.35–2.77 Å. In the third Na site, Na is bonded to six equivalent O atoms to form NaO6 octahedra that share corners with six equivalent SiO4 tetrahedra and faces with two equivalent NaO6 octahedra. All Na–O bond lengths are 2.43 Å. Y is bonded to six O atoms to form YO6 octahedra that share corners with six SiO4 tetrahedra. There are a spread of Y–O bond distances ranging from 2.23–2.31 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 YO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 24–41°. There are a spread of Si–O bond distances ranging from 1.61–1.67 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one YO6 octahedra, corners with two NaO6 octahedra, and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–47°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. There are six inequivalent O sites. In the first O site, O is bonded in a 1-coordinate geometry to four Na and one Si atom. In the second O site, O is bonded in a distorted bent 150 degrees geometry to one Na and two Si atoms. In the third O site, O is bonded in a distorted bent 150 degrees geometry to one Y and one Si atom. In the fourth O site, O is bonded in a bent 150 degrees geometry to one Y and one Si atom. In the fifth O site, O is bonded in a distorted trigonal planar geometry to one Na and two Si atoms. In the sixth O site, O is bonded in a distorted trigonal non-coplanar geometry to one Na, one Y, and one Si atom.