DOI: 10.17188/1267702
title: Materials Data on Na6Si8O19 by Materials Project

description: Na6Si8O19 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 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.32–2.71 Å. In the second 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 2.37–3.05 Å. In the third Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with three NaO6 octahedra, corners with four SiO4 tetrahedra, edges with four NaO6 octahedra, and edges with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 23–38°. There are a spread of Na–O bond distances ranging from 2.39–2.77 Å. In the fourth Na1+ site, Na1+ is bonded to five O2- atoms to form distorted NaO5 trigonal bipyramids that share corners with four SiO4 tetrahedra, corners with two equivalent NaO5 trigonal bipyramids, an edgeedge with one SiO4 tetrahedra, and edges with two equivalent NaO5 trigonal bipyramids. There are a spread of Na–O bond distances ranging from 2.40–2.63 Å. In the fifth Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with three NaO6 octahedra, corners with four SiO4 tetrahedra, a cornercorner with one NaO5 trigonal bipyramid, edges with two equivalent NaO6 octahedra, and edges with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 26–38°. There are a spread of Na–O bond distances ranging from 2.31–2.69 Å. In the sixth Na1+ site, Na1+ is bonded to five O2- atoms to form distorted NaO5 trigonal bipyramids that share a cornercorner with one NaO6 octahedra, corners with four SiO4 tetrahedra, corners with two equivalent NaO5 trigonal bipyramids, an edgeedge with one SiO4 tetrahedra, and edges with two equivalent NaO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 41°. There are a spread of Na–O bond distances ranging from 2.31–2.70 Å. There are eight inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.64 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three SiO4 tetrahedra, a cornercorner with one NaO5 trigonal bipyramid, and an edgeedge with one NaO6 octahedra. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with three SiO4 tetrahedra, corners with two NaO5 trigonal bipyramids, and an edgeedge with one NaO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 67°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three SiO4 tetrahedra, corners with two NaO5 trigonal bipyramids, and an edgeedge with one NaO5 trigonal bipyramid. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two NaO6 octahedra, corners with three SiO4 tetrahedra, and edges with two equivalent NaO6 octahedra. The corner-sharing octahedra tilt angles range from 52–68°. There are a spread of Si–O bond distances ranging from 1.59–1.66 Å. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three NaO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 58–60°. There are a spread of Si–O bond distances ranging from 1.61–1.64 Å. In the seventh Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three SiO4 tetrahedra and corners with two NaO5 trigonal bipyramids. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the eighth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two NaO6 octahedra, corners with three SiO4 tetrahedra, a cornercorner with one NaO5 trigonal bipyramid, and an edgeedge with one NaO6 octahedra. The corner-sharing octahedra tilt angles range from 60–67°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. There are nineteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to four Na1+ and one Si4+ atom. In the second O2- site, O2- is bonded in a linear geometry to two Si4+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two Si4+ atoms. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to four Na1+ and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Si4+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Na1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a 5-coordinate geometry to four Na1+ and one Si4+ atom. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the ninth O2- site, O2- is bonded in a 5-coordinate geometry to four Na1+ and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a 5-coordinate geometry to four Na1+ and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the fourteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Si4+ atoms. In the fifteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the sixteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Na1+ and two Si4+ atoms. In the seventeenth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Si4+ atoms. In the eighteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two Si4+ atoms. In the nineteenth O2- site, O2- is bonded in a 5-coordinate geometry to four Na1+ and one Si4+ atom.