Nd4(SiS4)3 crystallizes in the trigonal R3c space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 9-coordinate geometry to three equivalent S(3) and six equivalent S(2) atoms. In the second Nd site, Nd(2) is bonded in a 7-coordinate geometry to one S(2), two equivalent S(3), two equivalent S(4), and three equivalent S(1) atoms. Si(1) is bonded in a tetrahedral geometry to one S(1), one S(2), one S(3), and one S(4) atom. There are four inequivalent S sites. In the first S site, S(1) is bonded in a 4-coordinate geometry to three equivalent Nd(2) and one Si(1) atom. In the second S site, S(2) is bonded to one Nd(2), two equivalent Nd(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing SNd3Si tetrahedra. In the third S site, S(3) is bonded in a 4-coordinate geometry to one Nd(1), two equivalent Nd(2), and one Si(1) atom. In the fourth S site, S(4) is bonded in a 3-coordinate geometry to two equivalent Nd(2) and one Si(1) atom.
Nd4(SiS4)3 crystallizes in the trigonal R3c space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 9-coordinate geometry to three equivalent S(3) and six equivalent S(2) atoms. All Nd(1)-S(3) bond lengths are 3.37 Å. There are three shorter (2.88 Å) and three longer (2.89 Å) Nd(1)-S(2) bond lengths. In the second Nd site, Nd(2) is bonded in a 7-coordinate geometry to one S(2), two equivalent S(3), two equivalent S(4), and three equivalent S(1) atoms. The Nd(2)-S(2) bond length is 2.89 Å. There is one shorter (3.00 Å) and one longer (3.05 Å) Nd(2)-S(3) bond length. There is one shorter (2.86 Å) and one longer (2.94 Å) Nd(2)-S(4) bond length. There are a spread of Nd(2)-S(1) bond distances ranging from 2.88-3.53 Å. Si(1) is bonded in a tetrahedral geometry to one S(1), one S(2), one S(3), and one S(4) atom. The Si(1)-S(1) bond length is 2.11 Å. The Si(1)-S(2) bond length is 2.16 Å. The Si(1)-S(3) bond length is 2.11 Å. The Si(1)-S(4) bond length is 2.12 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded in a 4-coordinate geometry to three equivalent Nd(2) and one Si(1) atom. In the second S site, S(2) is bonded to one Nd(2), two equivalent Nd(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing SNd3Si tetrahedra. In the third S site, S(3) is bonded in a 4-coordinate geometry to one Nd(1), two equivalent Nd(2), and one Si(1) atom. In the fourth S site, S(4) is bonded in a 3-coordinate geometry to two equivalent Nd(2) and one Si(1) atom.