MgNd2S4 is Spinel-like structured and crystallizes in the orthorhombic Pnma space group. Mg(1) is bonded to one S(2), one S(3), and two equivalent S(1) atoms to form MgS4 tetrahedra that share corners with two equivalent Nd(1)S6 octahedra, corners with four equivalent Nd(2)S6 octahedra,  an edgeedge with one Nd(2)S6 octahedra, and edges with two equivalent Nd(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 60-63°. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form NdS6 octahedra that share corners with four equivalent Nd(2)S6 octahedra, corners with two equivalent Mg(1)S4 tetrahedra, edges with two equivalent Nd(1)S6 octahedra, edges with two equivalent Nd(2)S6 octahedra, and edges with two equivalent Mg(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-57°. In the second Nd site, Nd(2) is bonded to one S(2), one S(3), and four equivalent S(1) atoms to form NdS6 octahedra that share corners with four equivalent Nd(1)S6 octahedra, corners with four equivalent Nd(2)S6 octahedra, corners with four equivalent Mg(1)S4 tetrahedra, edges with two equivalent Nd(1)S6 octahedra, and  an edgeedge with one Mg(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-57°. There are three inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Nd(1), and two equivalent Nd(2) atoms. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Nd(2), and two equivalent Nd(1) atoms. In the third S site, S(3) is bonded to one Mg(1), one Nd(2), and two equivalent Nd(1) atoms to form distorted corner-sharing SNd3Mg tetrahedra.
MgNd2S4 is Spinel-like structured and crystallizes in the orthorhombic Pnma space group. Mg(1) is bonded to one S(2), one S(3), and two equivalent S(1) atoms to form MgS4 tetrahedra that share corners with two equivalent Nd(1)S6 octahedra, corners with four equivalent Nd(2)S6 octahedra,  an edgeedge with one Nd(2)S6 octahedra, and edges with two equivalent Nd(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 60-63°. The Mg(1)-S(2) bond length is 2.48 Å. The Mg(1)-S(3) bond length is 2.42 Å. Both Mg(1)-S(1) bond lengths are 2.47 Å. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form NdS6 octahedra that share corners with four equivalent Nd(2)S6 octahedra, corners with two equivalent Mg(1)S4 tetrahedra, edges with two equivalent Nd(1)S6 octahedra, edges with two equivalent Nd(2)S6 octahedra, and edges with two equivalent Mg(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-57°. Both Nd(1)-S(1) bond lengths are 2.88 Å. Both Nd(1)-S(2) bond lengths are 2.83 Å. Both Nd(1)-S(3) bond lengths are 2.82 Å. In the second Nd site, Nd(2) is bonded to one S(2), one S(3), and four equivalent S(1) atoms to form NdS6 octahedra that share corners with four equivalent Nd(1)S6 octahedra, corners with four equivalent Nd(2)S6 octahedra, corners with four equivalent Mg(1)S4 tetrahedra, edges with two equivalent Nd(1)S6 octahedra, and  an edgeedge with one Mg(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-57°. The Nd(2)-S(2) bond length is 2.81 Å. The Nd(2)-S(3) bond length is 2.85 Å. There are two shorter (2.89 Å) and two longer (2.92 Å) Nd(2)-S(1) bond lengths. There are three inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Nd(1), and two equivalent Nd(2) atoms. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Nd(2), and two equivalent Nd(1) atoms. In the third S site, S(3) is bonded to one Mg(1), one Nd(2), and two equivalent Nd(1) atoms to form distorted corner-sharing SNd3Mg tetrahedra.