Materials Data on SmYSe2 by Materials Project
SmYSe2 is Caswellsilverite structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Sm is bonded to six equivalent Se atoms to form SmSe6 octahedra that share corners with six equivalent YSe6 octahedra, edges with six equivalent SmSe6 octahedra, and edges with six equivalent YSe6 octahedra. The corner-sharing octahedral tilt angles are 2°. All Sm–Se bond lengths are 2.96 Å. Y is bonded to six equivalent Se atoms to form YSe6 octahedra that share corners with six equivalent SmSe6 octahedra, edges with six equivalent SmSe6 octahedra, and edges with six equivalent YSe6 octahedra. The corner-sharing octahedral tilt angles are 2°. All Y–Se bond lengths are 2.88 Å. Se is bonded to three equivalent Sm and three equivalent Y atoms to form a mixture of edge and corner-sharing SeSm3Y3 octahedra. The corner-sharing octahedral tilt angles are 0°.