Fe2SiS4 is Spinel-like structured and crystallizes in the trigonal P-3m1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form FeS6 octahedra that share corners with four equivalent Fe(2)S6 octahedra, corners with two equivalent Si(1)S4 tetrahedra, edges with four equivalent Fe(1)S6 octahedra, and edges with two equivalent Si(1)S4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. In the second Fe site, Fe(2) is bonded to six equivalent S(1) atoms to form FeS6 octahedra that share corners with twelve equivalent Fe(1)S6 octahedra and corners with six equivalent Si(1)S4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. Si(1) is bonded to one S(2) and three equivalent S(1) atoms to form SiS4 tetrahedra that share corners with three equivalent Fe(1)S6 octahedra, corners with three equivalent Fe(2)S6 octahedra, and edges with three equivalent Fe(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 60-63°. There are two inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Fe(2), two equivalent Fe(1), and one Si(1) atom. In the second S site, S(2) is bonded to three equivalent Fe(1) and one Si(1) atom to form corner-sharing SFe3Si tetrahedra.
Fe2SiS4 is Spinel-like structured and crystallizes in the trigonal P-3m1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form FeS6 octahedra that share corners with four equivalent Fe(2)S6 octahedra, corners with two equivalent Si(1)S4 tetrahedra, edges with four equivalent Fe(1)S6 octahedra, and edges with two equivalent Si(1)S4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. Both Fe(1)-S(2) bond lengths are 2.20 Å. All Fe(1)-S(1) bond lengths are 2.36 Å. In the second Fe site, Fe(2) is bonded to six equivalent S(1) atoms to form FeS6 octahedra that share corners with twelve equivalent Fe(1)S6 octahedra and corners with six equivalent Si(1)S4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. All Fe(2)-S(1) bond lengths are 2.40 Å. Si(1) is bonded to one S(2) and three equivalent S(1) atoms to form SiS4 tetrahedra that share corners with three equivalent Fe(1)S6 octahedra, corners with three equivalent Fe(2)S6 octahedra, and edges with three equivalent Fe(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 60-63°. The Si(1)-S(2) bond length is 2.15 Å. All Si(1)-S(1) bond lengths are 2.15 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Fe(2), two equivalent Fe(1), and one Si(1) atom. In the second S site, S(2) is bonded to three equivalent Fe(1) and one Si(1) atom to form corner-sharing SFe3Si tetrahedra.