Sm(AlGe)2 crystallizes in the trigonal P-3m1 space group. Sm(1) is bonded to six equivalent Ge(1) atoms to form SmGe6 octahedra that share corners with twelve equivalent Al(1)Ge4 tetrahedra, edges with six equivalent Sm(1)Ge6 octahedra, and edges with six equivalent Al(1)Ge4 tetrahedra. Al(1) is bonded to four equivalent Ge(1) atoms to form distorted AlGe4 tetrahedra that share corners with six equivalent Sm(1)Ge6 octahedra, corners with six equivalent Al(1)Ge4 tetrahedra, edges with three equivalent Sm(1)Ge6 octahedra, and edges with three equivalent Al(1)Ge4 tetrahedra. The corner-sharing octahedral tilt angles range from 22-54°. Ge(1) is bonded to three equivalent Sm(1) and four equivalent Al(1) atoms to form a mixture of distorted edge and corner-sharing GeSm3Al4 pentagonal bipyramids.
Sm(AlGe)2 crystallizes in the trigonal P-3m1 space group. Sm(1) is bonded to six equivalent Ge(1) atoms to form SmGe6 octahedra that share corners with twelve equivalent Al(1)Ge4 tetrahedra, edges with six equivalent Sm(1)Ge6 octahedra, and edges with six equivalent Al(1)Ge4 tetrahedra. All Sm(1)-Ge(1) bond lengths are 3.04 Å. Al(1) is bonded to four equivalent Ge(1) atoms to form distorted AlGe4 tetrahedra that share corners with six equivalent Sm(1)Ge6 octahedra, corners with six equivalent Al(1)Ge4 tetrahedra, edges with three equivalent Sm(1)Ge6 octahedra, and edges with three equivalent Al(1)Ge4 tetrahedra. The corner-sharing octahedral tilt angles range from 22-54°. There are three shorter (2.53 Å) and one longer (2.56 Å) Al(1)-Ge(1) bond length. Ge(1) is bonded to three equivalent Sm(1) and four equivalent Al(1) atoms to form a mixture of distorted edge and corner-sharing GeSm3Al4 pentagonal bipyramids.