Materials Data on Sm2SeO2 by Materials Project

Sm2SeO2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Sm3+ is bonded in a 4-coordinate geometry to three equivalent Se2- and four equivalent O2- atoms. All Sm–Se bond lengths are 3.05 Å. There are one shorter (2.35 Å) and three longer (2.36 Å) Sm–O bond lengths. Se2- is bonded to six equivalent Sm3+ atoms to form distorted SeSm6 octahedra that share corners with twelve equivalent OSm4 tetrahedra, edges with six equivalent SeSm6 octahedra, and edges with six equivalent OSm4 tetrahedra. O2- is bonded to four equivalent Sm3+ atoms to form OSm4 tetrahedra that share corners with six equivalent SeSm6 octahedra, corners with six equivalent OSm4 tetrahedra, edges with three equivalent SeSm6 octahedra, and edges with three equivalent OSm4 tetrahedra. The corner-sharing octahedra tilt angles range from 27–48°.