Materials Data on Na2Si4O9 by Materials Project
Na2Si4O9 is Esseneite-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are six inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.48–2.68 Å. In the second Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.48–2.73 Å. In the third Na1+ site, Na1+ is bonded in a 7-coordinate geometry to nine O2- atoms. There are a spread of Na–O bond distances ranging from 2.43–3.01 Å. In the fourth Na1+ site, Na1+ is bonded in a 5-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.26–2.99 Å. In the fifth Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.29–2.95 Å. In the sixth Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.37–2.65 Å. There are twelve inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to six O2- atoms to form corner-sharing SiO6 octahedra. There are a spread of Si–O bond distances ranging from 1.78–1.85 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two SiO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 32–37°. There are a spread of Si–O bond distances ranging from 1.61–1.67 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two SiO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 26–55°. There are a spread of Si–O bond distances ranging from 1.60–1.68 Å. In the fourth Si4+ site, Si4+ is bonded to six O2- atoms to form corner-sharing SiO6 octahedra. There are a spread of Si–O bond distances ranging from 1.78–1.84 Å. In the fifth Si4+ site, Si4+ is bonded to six O2- atoms to form corner-sharing SiO6 octahedra. There are a spread of Si–O bond distances ranging from 1.78–1.81 Å. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent SiO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 32–53°. There are a spread of Si–O bond distances ranging from 1.61–1.69 Å. In the seventh Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two SiO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 21–45°. There are a spread of Si–O bond distances ranging from 1.60–1.67 Å. In the eighth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two SiO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 38–51°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the ninth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent SiO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 40–48°. There are a spread of Si–O bond distances ranging from 1.61–1.68 Å. In the tenth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two SiO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 20–44°. There are a spread of Si–O bond distances ranging from 1.60–1.67 Å. In the eleventh Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent SiO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 35–49°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the twelfth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two SiO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–51°. There are a spread of Si–O bond distances ranging from 1.61–1.68 Å. There are twenty-seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Si4+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Si4+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Si4+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Na1+ and two Si4+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two Na1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Si4+ atoms. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+ and two Si4+ atoms. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to two Na1+ and two Si4+ atoms. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to two Na1+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+ and two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Na1+ and two Si4+ atoms. In the thirteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+ and two Si4+ atoms. In the fourteenth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+ and two Si4+ atoms. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+ and two Si4+ atoms. In the sixteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two Si4+ atoms. In the seventeenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Na1+ and two Si4+ atoms. In the eighteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Si4+ atoms. In the nineteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two Si4+ atoms. In the twentieth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Si4+ atoms. In the twenty-first O2- site, O2- is bonded in a 2-coordinate geometry to two Na1+ and two Si4+ atoms. In the twenty-second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Na1+ and two Si4+ atoms. In the twenty-third O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+ and two Si4+ atoms. In the twenty-fourth O2- site, O2- is bonded in a distorted linear geometry to two Na1+ and two Si4+ atoms. In the twenty-fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+ and two Si4+ atoms. In the twenty-sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+ and two Si4+ atoms. In the twenty-seventh O2- site, O2- is bonded in a 2-coordinate geometry to two Na1+ and two Si4+ atoms.