Gd2S3 crystallizes in the tetragonal I-42d space group. There are three inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 8-coordinate geometry to two equivalent S(1), two equivalent S(3), and four equivalent S(2) atoms. In the second Gd site, Gd(2) is bonded to two equivalent S(2), two equivalent S(3), and four equivalent S(1) atoms to form distorted edge-sharing GdS8 hexagonal bipyramids. In the third Gd site, Gd(3) is bonded in a 8-coordinate geometry to two equivalent S(1), three equivalent S(2), and three equivalent S(3) atoms. There are three inequivalent S sites. In the first S site, S(1) is bonded to one Gd(1), two equivalent Gd(2), and two equivalent Gd(3) atoms to form SGd5 trigonal bipyramids that share corners with five equivalent S(2)Gd6 octahedra, corners with four equivalent S(3)Gd5 square pyramids, corners with four equivalent S(1)Gd5 trigonal bipyramids, edges with three equivalent S(2)Gd6 octahedra, edges with four equivalent S(3)Gd5 square pyramids,  an edgeedge with one S(1)Gd5 trigonal bipyramid,  a faceface with one S(2)Gd6 octahedra, and  a faceface with one S(1)Gd5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 24-50°. In the second S site, S(2) is bonded to one Gd(2), two equivalent Gd(1), and three equivalent Gd(3) atoms to form distorted SGd6 octahedra that share corners with three equivalent S(2)Gd6 octahedra, corners with seven equivalent S(3)Gd5 square pyramids, corners with five equivalent S(1)Gd5 trigonal bipyramids, edges with two equivalent S(2)Gd6 octahedra,  an edgeedge with one S(3)Gd5 square pyramid, edges with three equivalent S(1)Gd5 trigonal bipyramids, faces with two equivalent S(2)Gd6 octahedra, faces with two equivalent S(3)Gd5 square pyramids, and  a faceface with one S(1)Gd5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 19-49°. In the third S site, S(3) is bonded to one Gd(1), one Gd(2), and three equivalent Gd(3) atoms to form distorted SGd5 square pyramids that share corners with seven equivalent S(2)Gd6 octahedra, corners with five equivalent S(3)Gd5 square pyramids, corners with four equivalent S(1)Gd5 trigonal bipyramids,  an edgeedge with one S(2)Gd6 octahedra, edges with four equivalent S(1)Gd5 trigonal bipyramids, faces with two equivalent S(2)Gd6 octahedra, and  a faceface with one S(3)Gd5 square pyramid. The corner-sharing octahedral tilt angles range from 13-54°.
Gd2S3 crystallizes in the tetragonal I-42d space group. There are three inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 8-coordinate geometry to two equivalent S(1), two equivalent S(3), and four equivalent S(2) atoms. Both Gd(1)-S(1) bond lengths are 2.78 Å. Both Gd(1)-S(3) bond lengths are 3.01 Å. There are two shorter (2.80 Å) and two longer (2.98 Å) Gd(1)-S(2) bond lengths. In the second Gd site, Gd(2) is bonded to two equivalent S(2), two equivalent S(3), and four equivalent S(1) atoms to form distorted edge-sharing GdS8 hexagonal bipyramids. Both Gd(2)-S(2) bond lengths are 3.08 Å. Both Gd(2)-S(3) bond lengths are 2.82 Å. There are two shorter (2.80 Å) and two longer (3.00 Å) Gd(2)-S(1) bond lengths. In the third Gd site, Gd(3) is bonded in a 8-coordinate geometry to two equivalent S(1), three equivalent S(2), and three equivalent S(3) atoms. There is one shorter (2.77 Å) and one longer (3.00 Å) Gd(3)-S(1) bond length. There are a spread of Gd(3)-S(2) bond distances ranging from 2.80-3.18 Å. There are a spread of Gd(3)-S(3) bond distances ranging from 2.77-3.00 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded to one Gd(1), two equivalent Gd(2), and two equivalent Gd(3) atoms to form SGd5 trigonal bipyramids that share corners with five equivalent S(2)Gd6 octahedra, corners with four equivalent S(3)Gd5 square pyramids, corners with four equivalent S(1)Gd5 trigonal bipyramids, edges with three equivalent S(2)Gd6 octahedra, edges with four equivalent S(3)Gd5 square pyramids,  an edgeedge with one S(1)Gd5 trigonal bipyramid,  a faceface with one S(2)Gd6 octahedra, and  a faceface with one S(1)Gd5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 24-50°. In the second S site, S(2) is bonded to one Gd(2), two equivalent Gd(1), and three equivalent Gd(3) atoms to form distorted SGd6 octahedra that share corners with three equivalent S(2)Gd6 octahedra, corners with seven equivalent S(3)Gd5 square pyramids, corners with five equivalent S(1)Gd5 trigonal bipyramids, edges with two equivalent S(2)Gd6 octahedra,  an edgeedge with one S(3)Gd5 square pyramid, edges with three equivalent S(1)Gd5 trigonal bipyramids, faces with two equivalent S(2)Gd6 octahedra, faces with two equivalent S(3)Gd5 square pyramids, and  a faceface with one S(1)Gd5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 19-49°. In the third S site, S(3) is bonded to one Gd(1), one Gd(2), and three equivalent Gd(3) atoms to form distorted SGd5 square pyramids that share corners with seven equivalent S(2)Gd6 octahedra, corners with five equivalent S(3)Gd5 square pyramids, corners with four equivalent S(1)Gd5 trigonal bipyramids,  an edgeedge with one S(2)Gd6 octahedra, edges with four equivalent S(1)Gd5 trigonal bipyramids, faces with two equivalent S(2)Gd6 octahedra, and  a faceface with one S(3)Gd5 square pyramid. The corner-sharing octahedral tilt angles range from 13-54°.