SmFe2SiC crystallizes in the orthorhombic Cmcm space group. Sm(1) is bonded in a 4-coordinate geometry to three equivalent Si(1) and four equivalent C(1) atoms. Fe(1) is bonded in a single-bond geometry to three equivalent Si(1) and one C(1) atom. Si(1) is bonded in a 9-coordinate geometry to three equivalent Sm(1) and six equivalent Fe(1) atoms. C(1) is bonded to four equivalent Sm(1) and two equivalent Fe(1) atoms to form a mixture of corner and edge-sharing CSm4Fe2 octahedra. The corner-sharing octahedral tilt angles are 24°.
SmFe2SiC crystallizes in the orthorhombic Cmcm space group. Sm(1) is bonded in a 4-coordinate geometry to three equivalent Si(1) and four equivalent C(1) atoms. There is one shorter (2.94 Å) and two longer (3.01 Å) Sm(1)-Si(1) bond lengths. All Sm(1)-C(1) bond lengths are 2.62 Å. Fe(1) is bonded in a single-bond geometry to three equivalent Si(1) and one C(1) atom. All Fe(1)-Si(1) bond lengths are 2.39 Å. The Fe(1)-C(1) bond length is 1.80 Å. Si(1) is bonded in a 9-coordinate geometry to three equivalent Sm(1) and six equivalent Fe(1) atoms. C(1) is bonded to four equivalent Sm(1) and two equivalent Fe(1) atoms to form a mixture of corner and edge-sharing CSm4Fe2 octahedra. The corner-sharing octahedral tilt angles are 24°.