Materials Data on Na3ScSi2O7 by Materials Project

Abstract

Na3ScSi2O7 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 2.37–2.50 Å. In the second 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 2.38–2.50 Å. Sc3+ is bonded to six O2- atoms to form ScO6 octahedra that share corners with six equivalent SiO4 tetrahedra. There are a spread of Sc–O bond distances ranging from 2.08–2.16 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent ScO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 16–43°. There are a spread of Si–O bond distances ranging from 1.63–1.68 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two equivalent Si4+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Sc3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Sc3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Sc3+, and one Si4+ atom.