Materials Data on Na2Al2(SiO4)3 by Materials Project

Abstract

Na2Al2(SiO4)3 crystallizes in the orthorhombic Fdd2 space group. The structure is three-dimensional. Na is bonded to six O atoms to form distorted NaO6 pentagonal pyramids that share corners with two equivalent AlO4 tetrahedra, corners with two equivalent SiO4 tetrahedra, edges with two equivalent NaO6 pentagonal pyramids, an edgeedge with one AlO4 tetrahedra, and an edgeedge with one SiO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.37–2.53 Å. Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with two equivalent NaO6 pentagonal pyramids, corners with four SiO4 tetrahedra, and an edgeedge with one NaO6 pentagonal pyramid. There are a spread of Al–O bond distances ranging from 1.75–1.78 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 AlO4 tetrahedra and corners with two equivalent SiO4 tetrahedra. There is two shorter (1.63 Å) and two longer (1.65 Å) Si–O bond length. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent NaO6 pentagonal pyramids, a cornercorner with one SiO4 tetrahedra, corners with three equivalent AlO4 tetrahedra, and an edgeedge with one NaO6 pentagonal pyramid. There is two shorter (1.63 Å) and two longer (1.65 Å) Si–O bond length. There are six inequivalent O sites. In the first O site, O is bonded in a 3-coordinate geometry to one Na, one Al, and one Si atom. In the second O site, O is bonded in a 3-coordinate geometry to one Na, one Al, and one Si atom. In the third O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fourth O site, O is bonded in an L-shaped geometry to two equivalent Na atoms. In the fifth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the sixth O site, O is bonded in a 4-coordinate geometry to two equivalent Na, one Al, and one Si atom.