Materials Data on NaSc(SiO3)2 by Materials Project

Abstract

NaScSi2O6 is Esseneite structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.44–3.01 Å. Sc3+ is bonded to six O2- atoms to form ScO6 octahedra that share corners with six equivalent SiO4 tetrahedra and edges with two equivalent ScO6 octahedra. There are a spread of Sc–O bond distances ranging from 2.03–2.23 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent ScO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 31–58°. There are a spread of Si–O bond distances ranging from 1.61–1.67 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Na1+ and two equivalent Si4+ atoms. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+, one Sc3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two equivalent Sc3+, and one Si4+ atom.