MgCeS3 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 Ce(1)S6 octahedra, edges with three equivalent Mg(1)S6 octahedra, and  a faceface with one Ce(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 43-62°. Ce(1) is bonded to six equivalent S(1) atoms to form CeS6 octahedra that share corners with nine equivalent Mg(1)S6 octahedra, edges with three equivalent Ce(1)S6 octahedra, and  a faceface with one Mg(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 43-62°. S(1) is bonded to two equivalent Mg(1) and two equivalent Ce(1) atoms to form a mixture of distorted edge and corner-sharing SCe2Mg2 trigonal pyramids.
MgCeS3 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 Ce(1)S6 octahedra, edges with three equivalent Mg(1)S6 octahedra, and  a faceface with one Ce(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 43-62°. There are three shorter (2.63 Å) and three longer (2.66 Å) Mg(1)-S(1) bond lengths. Ce(1) is bonded to six equivalent S(1) atoms to form CeS6 octahedra that share corners with nine equivalent Mg(1)S6 octahedra, edges with three equivalent Ce(1)S6 octahedra, and  a faceface with one Mg(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 43-62°. There are three shorter (2.72 Å) and three longer (2.75 Å) Ce(1)-S(1) bond lengths. S(1) is bonded to two equivalent Mg(1) and two equivalent Ce(1) atoms to form a mixture of distorted edge and corner-sharing SCe2Mg2 trigonal pyramids.