MgDyS3 is Ilmenite structured and crystallizes in the trigonal R-3 space group. Mg(1) is bonded to six equivalent S(1) atoms to form MgS6 octahedra that share corners with nine equivalent Dy(1)S6 octahedra, edges with three equivalent Mg(1)S6 octahedra, and  a faceface with one Dy(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 46-57°. Dy(1) is bonded to six equivalent S(1) atoms to form DyS6 octahedra that share corners with nine equivalent Mg(1)S6 octahedra, edges with three equivalent Dy(1)S6 octahedra, and  a faceface with one Mg(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 46-57°. S(1) is bonded to two equivalent Mg(1) and two equivalent Dy(1) atoms to form a mixture of distorted edge and corner-sharing SDy2Mg2 trigonal pyramids.
MgDyS3 is Ilmenite structured and crystallizes in the trigonal R-3 space group. Mg(1) is bonded to six equivalent S(1) atoms to form MgS6 octahedra that share corners with nine equivalent Dy(1)S6 octahedra, edges with three equivalent Mg(1)S6 octahedra, and  a faceface with one Dy(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 46-57°. There are three shorter (2.57 Å) and three longer (2.67 Å) Mg(1)-S(1) bond lengths. Dy(1) is bonded to six equivalent S(1) atoms to form DyS6 octahedra that share corners with nine equivalent Mg(1)S6 octahedra, edges with three equivalent Dy(1)S6 octahedra, and  a faceface with one Mg(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 46-57°. There are three shorter (2.71 Å) and three longer (2.74 Å) Dy(1)-S(1) bond lengths. S(1) is bonded to two equivalent Mg(1) and two equivalent Dy(1) atoms to form a mixture of distorted edge and corner-sharing SDy2Mg2 trigonal pyramids.