Materials Data on La2(SiO3)3 by Materials Project

Abstract

La2(SiO3)3 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. La3+ is bonded to six equivalent O2- atoms to form distorted LaO6 octahedra that share corners with six equivalent SiO4 tetrahedra and edges with three equivalent LaO6 octahedra. There are three shorter (2.38 Å) and three longer (2.56 Å) La–O bond lengths. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four equivalent LaO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–64°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Si4+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent La3+ and one Si4+ atom.