Materials Data on Na6CaZr(SiO3)6 by Materials Project

Abstract

Na6CaZr(SiO3)6 crystallizes in the trigonal R3c space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 2-coordinate geometry to nine O2- atoms. There are a spread of Na–O bond distances ranging from 2.29–3.14 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 2.27–3.05 Å. Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with six equivalent SiO4 tetrahedra and a faceface with one ZrO6 octahedra. There are three shorter (2.28 Å) and three longer (2.57 Å) Ca–O bond lengths. Zr4+ is bonded to six O2- atoms to form ZrO6 octahedra that share corners with six SiO4 tetrahedra and a faceface with one CaO6 octahedra. There are three shorter (2.07 Å) and three longer (2.17 Å) Zr–O bond lengths. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one ZrO6 octahedra, corners with two equivalent CaO6 octahedra, and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 37–50°. There are a spread of Si–O bond distances ranging from 1.61–1.67 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one ZrO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 34°. There are a spread of Si–O bond distances ranging from 1.58–1.67 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded to three Na1+ and one Si4+ atom to form distorted corner-sharing ONa3Si trigonal pyramids. In the second O2- site, O2- is bonded in a 2-coordinate geometry to three Na1+, one Zr4+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to three Na1+ and two Si4+ atoms. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Na1+, one Ca2+, one Zr4+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to three Na1+, one Ca2+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to three Na1+ and two Si4+ atoms.