Materials Data on Na4SnO4 by Materials Project
Na4SnO4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share corners with four NaO5 square pyramids, corners with four equivalent NaO4 tetrahedra, corners with four equivalent SnO4 tetrahedra, and edges with two equivalent NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.33–2.42 Å. In the second Na1+ site, Na1+ is bonded to five O2- atoms to form NaO5 square pyramids that share corners with three equivalent NaO5 square pyramids, corners with three NaO4 tetrahedra, corners with three equivalent SnO4 tetrahedra, edges with five NaO5 square pyramids, an edgeedge with one SnO4 tetrahedra, and edges with two equivalent NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.37–2.60 Å. In the third Na1+ site, Na1+ is bonded to five O2- atoms to form NaO5 square pyramids that share corners with three equivalent NaO5 square pyramids, a cornercorner with one SnO4 tetrahedra, corners with five NaO4 tetrahedra, edges with five NaO5 square pyramids, an edgeedge with one NaO4 tetrahedra, and edges with two equivalent SnO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.41–2.64 Å. In the fourth Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share corners with four NaO5 square pyramids, corners with four equivalent NaO4 tetrahedra, corners with four equivalent SnO4 tetrahedra, and edges with three NaO5 square pyramids. There are three shorter (2.34 Å) and one longer (2.38 Å) Na–O bond lengths. Sn4+ is bonded to four O2- atoms to form SnO4 tetrahedra that share corners with four NaO5 square pyramids, corners with eight NaO4 tetrahedra, and edges with three NaO5 square pyramids. There are a spread of Sn–O bond distances ranging from 1.97–2.01 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to five Na1+ and one Sn4+ atom to form ONa5Sn octahedra that share corners with two equivalent ONa5Sn octahedra, corners with six equivalent ONa3Sn tetrahedra, and edges with six ONa5Sn octahedra. The corner-sharing octahedra tilt angles range from 10–13°. In the second O2- site, O2- is bonded to five Na1+ and one Sn4+ atom to form ONa5Sn octahedra that share corners with four ONa5Sn octahedra, corners with two equivalent ONa3Sn tetrahedra, and edges with eight ONa5Sn octahedra. The corner-sharing octahedra tilt angles range from 10–25°. In the third O2- site, O2- is bonded to five Na1+ and one Sn4+ atom to form distorted ONa5Sn octahedra that share corners with two equivalent ONa5Sn octahedra, corners with two equivalent ONa3Sn tetrahedra, and edges with nine ONa5Sn octahedra. The corner-sharing octahedra tilt angles range from 12–25°. In the fourth O2- site, O2- is bonded to three Na1+ and one Sn4+ atom to form ONa3Sn tetrahedra that share corners with ten ONa5Sn octahedra and an edgeedge with one ONa3Sn tetrahedra. The corner-sharing octahedra tilt angles range from 56–66°.