Eu2SiS4 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 8-coordinate geometry to one S(2), three equivalent S(3), and four equivalent S(1) atoms. In the second Eu site, Eu(2) is bonded in a 8-coordinate geometry to one S(3), three equivalent S(2), and four equivalent S(1) atoms. Si(1) is bonded in a tetrahedral geometry to one S(2), one S(3), and two equivalent S(1) atoms. There are three inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Eu(1), two equivalent Eu(2), and one Si(1) atom to form a mixture of distorted corner, face, and edge-sharing SEu4Si square pyramids. In the second S site, S(2) is bonded in a 5-coordinate geometry to one Eu(1), three equivalent Eu(2), and one Si(1) atom. In the third S site, S(3) is bonded in a 5-coordinate geometry to one Eu(2), three equivalent Eu(1), and one Si(1) atom.
Eu2SiS4 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 8-coordinate geometry to one S(2), three equivalent S(3), and four equivalent S(1) atoms. The Eu(1)-S(2) bond length is 2.92 Å. There is one shorter (2.99 Å) and two longer (3.48 Å) Eu(1)-S(3) bond lengths. There are two shorter (2.97 Å) and two longer (3.07 Å) Eu(1)-S(1) bond lengths. In the second Eu site, Eu(2) is bonded in a 8-coordinate geometry to one S(3), three equivalent S(2), and four equivalent S(1) atoms. The Eu(2)-S(3) bond length is 3.08 Å. There is one shorter (2.98 Å) and two longer (3.42 Å) Eu(2)-S(2) bond lengths. There are two shorter (3.00 Å) and two longer (3.08 Å) Eu(2)-S(1) bond lengths. Si(1) is bonded in a tetrahedral geometry to one S(2), one S(3), and two equivalent S(1) atoms. The Si(1)-S(2) bond length is 2.12 Å. The Si(1)-S(3) bond length is 2.12 Å. Both Si(1)-S(1) bond lengths are 2.12 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Eu(1), two equivalent Eu(2), and one Si(1) atom to form a mixture of distorted corner, face, and edge-sharing SEu4Si square pyramids. In the second S site, S(2) is bonded in a 5-coordinate geometry to one Eu(1), three equivalent Eu(2), and one Si(1) atom. In the third S site, S(3) is bonded in a 5-coordinate geometry to one Eu(2), three equivalent Eu(1), and one Si(1) atom.