ThFe2SiC crystallizes in the orthorhombic Cmcm space group. Th(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 Th(1) and six equivalent Fe(1) atoms. C(1) is bonded to four equivalent Th(1) and two equivalent Fe(1) atoms to form a mixture of distorted corner and edge-sharing CTh4Fe2 octahedra. The corner-sharing octahedral tilt angles are 27°.
ThFe2SiC crystallizes in the orthorhombic Cmcm space group. Th(1) is bonded in a 4-coordinate geometry to three equivalent Si(1) and four equivalent C(1) atoms. All Th(1)-Si(1) bond lengths are 3.03 Å. All Th(1)-C(1) bond lengths are 2.66 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 2.42 Å. The Fe(1)-C(1) bond length is 1.80 Å. Si(1) is bonded in a 9-coordinate geometry to three equivalent Th(1) and six equivalent Fe(1) atoms. C(1) is bonded to four equivalent Th(1) and two equivalent Fe(1) atoms to form a mixture of distorted corner and edge-sharing CTh4Fe2 octahedra. The corner-sharing octahedral tilt angles are 27°.