Mg2MoNi3S8 is Spinel-derived structured and crystallizes in the trigonal R-3m space group. Mg(1) is bonded to one S(2) and three equivalent S(1) atoms to form MgS4 tetrahedra that share corners with three equivalent Mo(1)S6 octahedra and corners with nine equivalent Ni(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 58-64°. Mo(1) is bonded to six equivalent S(1) atoms to form MoS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra and edges with six equivalent Ni(1)S6 octahedra. Ni(1) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form NiS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Mo(1)S6 octahedra, and edges with four equivalent Ni(1)S6 octahedra. There are two inequivalent S sites. In the first S site, S(1) is bonded to one Mg(1), one Mo(1), and two equivalent Ni(1) atoms to form distorted SMgNi2Mo trigonal pyramids that share corners with three equivalent S(2)MgNi3 tetrahedra, corners with nine equivalent S(1)MgNi2Mo trigonal pyramids,  an edgeedge with one S(2)MgNi3 tetrahedra, and edges with two equivalent S(1)MgNi2Mo trigonal pyramids. In the second S site, S(2) is bonded to one Mg(1) and three equivalent Ni(1) atoms to form distorted SMgNi3 tetrahedra that share corners with three equivalent S(2)MgNi3 tetrahedra, corners with nine equivalent S(1)MgNi2Mo trigonal pyramids, and edges with three equivalent S(1)MgNi2Mo trigonal pyramids.
Mg2MoNi3S8 is Spinel-derived structured and crystallizes in the trigonal R-3m space group. Mg(1) is bonded to one S(2) and three equivalent S(1) atoms to form MgS4 tetrahedra that share corners with three equivalent Mo(1)S6 octahedra and corners with nine equivalent Ni(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 58-64°. The Mg(1)-S(2) bond length is 2.47 Å. All Mg(1)-S(1) bond lengths are 2.45 Å. Mo(1) is bonded to six equivalent S(1) atoms to form MoS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra and edges with six equivalent Ni(1)S6 octahedra. All Mo(1)-S(1) bond lengths are 2.45 Å. Ni(1) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form NiS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Mo(1)S6 octahedra, and edges with four equivalent Ni(1)S6 octahedra. Both Ni(1)-S(2) bond lengths are 2.35 Å. All Ni(1)-S(1) bond lengths are 2.35 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded to one Mg(1), one Mo(1), and two equivalent Ni(1) atoms to form distorted SMgNi2Mo trigonal pyramids that share corners with three equivalent S(2)MgNi3 tetrahedra, corners with nine equivalent S(1)MgNi2Mo trigonal pyramids,  an edgeedge with one S(2)MgNi3 tetrahedra, and edges with two equivalent S(1)MgNi2Mo trigonal pyramids. In the second S site, S(2) is bonded to one Mg(1) and three equivalent Ni(1) atoms to form distorted SMgNi3 tetrahedra that share corners with three equivalent S(2)MgNi3 tetrahedra, corners with nine equivalent S(1)MgNi2Mo trigonal pyramids, and edges with three equivalent S(1)MgNi2Mo trigonal pyramids.