Materials Data on Sm2O3 by Materials Project

Abstract

Sm2O3 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Sm3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Sm–O bond distances ranging from 2.28–2.66 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Sm3+ atoms to form OSm4 tetrahedra that share corners with six equivalent OSm6 octahedra, corners with six equivalent OSm4 tetrahedra, edges with three equivalent OSm6 octahedra, and edges with three equivalent OSm4 tetrahedra. The corner-sharing octahedra tilt angles range from 18–56°. In the second O2- site, O2- is bonded to six equivalent Sm3+ atoms to form OSm6 octahedra that share corners with twelve equivalent OSm4 tetrahedra, edges with six equivalent OSm6 octahedra, and edges with six equivalent OSm4 tetrahedra.