Materials Data on K2Al2(SiO4)3 by Materials Project

Abstract

K2Al2(SiO4)3 crystallizes in the orthorhombic Fdd2 space group. The structure is three-dimensional. K is bonded in a 6-coordinate geometry to six O atoms. There are a spread of K–O bond distances ranging from 2.71–3.13 Å. Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.75–1.77 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. All Si–O bond lengths are 1.64 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three equivalent AlO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. There are six inequivalent O sites. In the first O site, O is bonded in a 2-coordinate geometry to one K, one Al, and one Si atom. In the second O site, O is bonded in a 3-coordinate geometry to one K, 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 a 2-coordinate geometry to two equivalent K 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 2-coordinate geometry to two equivalent K, one Al, and one Si atom.