Materials Data on Na2SiO9 by Materials Project
Na2SiO9 crystallizes in the monoclinic P2_1 space group. The structure is two-dimensional and consists of one Na2SiO9 sheet oriented in the (0, 0, 1) direction. there are two inequivalent Na sites. In the first Na site, Na is bonded in a 2-coordinate geometry to seven O atoms. There are a spread of Na–O bond distances ranging from 2.23–3.04 Å. In the second Na site, Na is bonded in a trigonal planar geometry to three O atoms. There are a spread of Na–O bond distances ranging from 2.27–2.32 Å. Si is bonded in a tetrahedral geometry to four O atoms. There are a spread of Si–O bond distances ranging from 1.59–1.86 Å. There are nine inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to one Na and one Si atom. In the second O site, O is bonded in a distorted single-bond geometry to one Si and one O atom. The O–O bond length is 1.33 Å. In the third O site, O is bonded in a distorted trigonal planar geometry to two equivalent Na and one Si atom. In the fourth O site, O is bonded in a distorted trigonal planar geometry to two Na and one Si atom. In the fifth O site, O is bonded in a linear geometry to one Na and one O atom. The O–O bond length is 1.25 Å. In the sixth O site, O is bonded in a bent 120 degrees geometry to one Na and one O atom. The O–O bond length is 1.23 Å. In the seventh O site, O is bonded in a distorted single-bond geometry to one Na and one O atom. In the eighth O site, O is bonded in a 1-coordinate geometry to one Na and two O atoms. The O–O bond length is 1.95 Å. In the ninth O site, O is bonded in a 2-coordinate geometry to one Na and two O atoms.