SmF3 crystallizes in the hexagonal P6_3/mcm space group. Sm(1) is bonded in a 12-coordinate geometry to two equivalent F(1), two equivalent F(2), and eight equivalent F(3) atoms. There are three inequivalent F sites. In the first F site, F(2) is bonded in a trigonal planar geometry to three equivalent Sm(1) atoms. In the second F site, F(3) is bonded to four equivalent Sm(1) atoms to form distorted FSm4 tetrahedra that share corners with three equivalent F(1)Sm6 octahedra, corners with nineteen equivalent F(3)Sm4 tetrahedra,  an edgeedge with one F(1)Sm6 octahedra, edges with three equivalent F(3)Sm4 tetrahedra,  a faceface with one F(1)Sm6 octahedra, and  a faceface with one F(3)Sm4 tetrahedra. The corner-sharing octahedral tilt angles range from 10-64°. In the third F site, F(1) is bonded to six equivalent Sm(1) atoms to form FSm6 octahedra that share corners with eighteen equivalent F(3)Sm4 tetrahedra, edges with six equivalent F(3)Sm4 tetrahedra, faces with two equivalent F(1)Sm6 octahedra, and faces with six equivalent F(3)Sm4 tetrahedra.
SmF3 crystallizes in the hexagonal P6_3/mcm space group. Sm(1) is bonded in a 12-coordinate geometry to two equivalent F(1), two equivalent F(2), and eight equivalent F(3) atoms. Both Sm(1)-F(1) bond lengths are 2.92 Å. Both Sm(1)-F(2) bond lengths are 2.35 Å. There are a spread of Sm(1)-F(3) bond distances ranging from 2.33-2.65 Å. There are three inequivalent F sites. In the first F site, F(2) is bonded in a trigonal planar geometry to three equivalent Sm(1) atoms. In the second F site, F(3) is bonded to four equivalent Sm(1) atoms to form distorted FSm4 tetrahedra that share corners with three equivalent F(1)Sm6 octahedra, corners with nineteen equivalent F(3)Sm4 tetrahedra,  an edgeedge with one F(1)Sm6 octahedra, edges with three equivalent F(3)Sm4 tetrahedra,  a faceface with one F(1)Sm6 octahedra, and  a faceface with one F(3)Sm4 tetrahedra. The corner-sharing octahedral tilt angles range from 10-64°. In the third F site, F(1) is bonded to six equivalent Sm(1) atoms to form FSm6 octahedra that share corners with eighteen equivalent F(3)Sm4 tetrahedra, edges with six equivalent F(3)Sm4 tetrahedra, faces with two equivalent F(1)Sm6 octahedra, and faces with six equivalent F(3)Sm4 tetrahedra.