Materials Data on Na2ZrSi6O19 by Materials Project
(Na2Zr(SiO3)6)2O2 crystallizes in the monoclinic C2 space group. The structure is three-dimensional and consists of two water molecules and one Na2Zr(SiO3)6 framework. In the Na2Zr(SiO3)6 framework, Na is bonded to seven O atoms to form distorted NaO7 hexagonal pyramids that share a cornercorner with one ZrO6 octahedra, corners with three SiO4 tetrahedra, an edgeedge with one ZrO6 octahedra, and edges with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 74°. There are a spread of Na–O bond distances ranging from 2.37–2.75 Å. Zr is bonded to six O atoms to form ZrO6 octahedra that share corners with two equivalent NaO7 hexagonal pyramids, corners with six SiO4 tetrahedra, and edges with two equivalent NaO7 hexagonal pyramids. There are a spread of Zr–O bond distances ranging from 2.08–2.14 Å. There are three inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one NaO7 hexagonal pyramid, a cornercorner with one ZrO6 octahedra, corners with two SiO4 tetrahedra, and an edgeedge with one NaO7 hexagonal pyramid. The corner-sharing octahedral tilt angles are 32°. There are a spread of Si–O bond distances ranging from 1.62–1.64 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one NaO7 hexagonal pyramid, a cornercorner with one ZrO6 octahedra, corners with two SiO4 tetrahedra, and an edgeedge with one NaO7 hexagonal pyramid. The corner-sharing octahedral tilt angles are 19°. There are a spread of Si–O bond distances ranging from 1.61–1.65 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one NaO7 hexagonal pyramid, a cornercorner with one ZrO6 octahedra, corners with two SiO4 tetrahedra, and an edgeedge with one NaO7 hexagonal pyramid. The corner-sharing octahedral tilt angles are 29°. There are a spread of Si–O bond distances ranging from 1.62–1.64 Å. There are ten inequivalent O sites. In the first O site, O is bonded in a 2-coordinate geometry to one Na and two Si atoms. In the second O site, O is bonded in a single-bond geometry to one Si atom. In the third O site, O is bonded in a 2-coordinate geometry to one Na, one Zr, and one Si atom. In the fourth O site, O is bonded in a 2-coordinate geometry to one Na, one Zr, and one Si atom. In the fifth O site, O is bonded in a 3-coordinate geometry to one Na, one Zr, and one Si atom. In the sixth O site, O is bonded in a bent 150 degrees geometry to two equivalent Si atoms. In the seventh O site, O is bonded in a distorted bent 120 degrees geometry to one Na and one Si atom. In the eighth O site, O is bonded in a linear geometry to two equivalent Si atoms. In the ninth O site, O is bonded in a distorted T-shaped geometry to one Na and two Si atoms. In the tenth O site, O is bonded in a bent 150 degrees geometry to one Na and one Si atom.