Gd3NbS3O4 crystallizes in the orthorhombic Pna2_1 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), one O(1), one O(2), one O(3), and one O(4) atom. In the second Gd site, Gd(2) is bonded in a 8-coordinate geometry to one S(3), two equivalent S(1), two equivalent S(2), one O(1), one O(2), and one O(4) atom. In the third Gd site, Gd(3) is bonded in a 9-coordinate geometry to one S(3), two equivalent S(1), two equivalent S(2), one O(1), one O(4), and two equivalent O(3) atoms. Nb(1) is bonded in a 4-coordinate geometry to one S(2), one S(3), one O(1), one O(2), one O(3), and one O(4) atom. There are three inequivalent S sites. In the first S site, S(1) is bonded in a 6-coordinate geometry to two equivalent Gd(1), two equivalent Gd(2), and two equivalent Gd(3) atoms. In the second S site, S(2) is bonded to two equivalent Gd(2), two equivalent Gd(3), and one Nb(1) atom to form distorted SGd4Nb trigonal bipyramids that share  a cornercorner with one O(4)Gd3Nb tetrahedra, corners with three equivalent S(3)Gd4Nb trigonal bipyramids, corners with five equivalent O(1)Gd3Nb trigonal pyramids, edges with two equivalent O(4)Gd3Nb tetrahedra,  an edgeedge with one S(3)Gd4Nb trigonal bipyramid, and edges with two equivalent S(2)Gd4Nb trigonal bipyramids. In the third S site, S(3) is bonded to one Gd(2), one Gd(3), two equivalent Gd(1), and one Nb(1) atom to form distorted SGd4Nb trigonal bipyramids that share  a cornercorner with one O(4)Gd3Nb tetrahedra, corners with two equivalent S(3)Gd4Nb trigonal bipyramids, corners with three equivalent S(2)Gd4Nb trigonal bipyramids, corners with three equivalent O(1)Gd3Nb trigonal pyramids, edges with two equivalent O(4)Gd3Nb tetrahedra,  an edgeedge with one S(2)Gd4Nb trigonal bipyramid, and  an edgeedge with one O(1)Gd3Nb trigonal pyramid. There are four inequivalent O sites. In the first O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Gd(1), one Gd(2), and one Nb(1) atom. In the second O site, O(3) is bonded in a 3-coordinate geometry to one Gd(1), two equivalent Gd(3), and one Nb(1) atom. In the third O site, O(4) is bonded to one Gd(1), one Gd(2), one Gd(3), and one Nb(1) atom to form OGd3Nb tetrahedra that share  a cornercorner with one S(2)Gd4Nb trigonal bipyramid,  a cornercorner with one S(3)Gd4Nb trigonal bipyramid, corners with two equivalent O(1)Gd3Nb trigonal pyramids, edges with two equivalent S(2)Gd4Nb trigonal bipyramids, edges with two equivalent S(3)Gd4Nb trigonal bipyramids, and  an edgeedge with one O(1)Gd3Nb trigonal pyramid. In the fourth O site, O(1) is bonded to one Gd(1), one Gd(2), one Gd(3), and one Nb(1) atom to form distorted OGd3Nb trigonal pyramids that share corners with two equivalent O(4)Gd3Nb tetrahedra, corners with three equivalent S(3)Gd4Nb trigonal bipyramids, corners with five equivalent S(2)Gd4Nb trigonal bipyramids,  an edgeedge with one O(4)Gd3Nb tetrahedra, and  an edgeedge with one S(3)Gd4Nb trigonal bipyramid.
Gd3NbS3O4 crystallizes in the orthorhombic Pna2_1 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), one O(1), one O(2), one O(3), and one O(4) atom. There is one shorter (2.77 Å) and one longer (3.14 Å) Gd(1)-S(1) bond length. There is one shorter (2.89 Å) and one longer (2.93 Å) Gd(1)-S(3) bond length. The Gd(1)-O(1) bond length is 2.47 Å. The Gd(1)-O(2) bond length is 2.27 Å. The Gd(1)-O(3) bond length is 2.31 Å. The Gd(1)-O(4) bond length is 2.29 Å. In the second Gd site, Gd(2) is bonded in a 8-coordinate geometry to one S(3), two equivalent S(1), two equivalent S(2), one O(1), one O(2), and one O(4) atom. The Gd(2)-S(3) bond length is 2.91 Å. There is one shorter (2.87 Å) and one longer (2.91 Å) Gd(2)-S(1) bond length. There is one shorter (2.92 Å) and one longer (2.95 Å) Gd(2)-S(2) bond length. The Gd(2)-O(1) bond length is 2.45 Å. The Gd(2)-O(2) bond length is 2.36 Å. The Gd(2)-O(4) bond length is 2.34 Å. In the third Gd site, Gd(3) is bonded in a 9-coordinate geometry to one S(3), two equivalent S(1), two equivalent S(2), one O(1), one O(4), and two equivalent O(3) atoms. The Gd(3)-S(3) bond length is 3.04 Å. There is one shorter (2.86 Å) and one longer (2.94 Å) Gd(3)-S(1) bond length. There is one shorter (2.93 Å) and one longer (2.96 Å) Gd(3)-S(2) bond length. The Gd(3)-O(1) bond length is 2.46 Å. The Gd(3)-O(4) bond length is 2.32 Å. There is one shorter (2.35 Å) and one longer (3.08 Å) Gd(3)-O(3) bond length. Nb(1) is bonded in a 4-coordinate geometry to one S(2), one S(3), one O(1), one O(2), one O(3), and one O(4) atom. The Nb(1)-S(2) bond length is 2.60 Å. The Nb(1)-S(3) bond length is 2.71 Å. The Nb(1)-O(1) bond length is 1.97 Å. The Nb(1)-O(2) bond length is 1.94 Å. The Nb(1)-O(3) bond length is 1.93 Å. The Nb(1)-O(4) bond length is 2.13 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded in a 6-coordinate geometry to two equivalent Gd(1), two equivalent Gd(2), and two equivalent Gd(3) atoms. In the second S site, S(2) is bonded to two equivalent Gd(2), two equivalent Gd(3), and one Nb(1) atom to form distorted SGd4Nb trigonal bipyramids that share  a cornercorner with one O(4)Gd3Nb tetrahedra, corners with three equivalent S(3)Gd4Nb trigonal bipyramids, corners with five equivalent O(1)Gd3Nb trigonal pyramids, edges with two equivalent O(4)Gd3Nb tetrahedra,  an edgeedge with one S(3)Gd4Nb trigonal bipyramid, and edges with two equivalent S(2)Gd4Nb trigonal bipyramids. In the third S site, S(3) is bonded to one Gd(2), one Gd(3), two equivalent Gd(1), and one Nb(1) atom to form distorted SGd4Nb trigonal bipyramids that share  a cornercorner with one O(4)Gd3Nb tetrahedra, corners with two equivalent S(3)Gd4Nb trigonal bipyramids, corners with three equivalent S(2)Gd4Nb trigonal bipyramids, corners with three equivalent O(1)Gd3Nb trigonal pyramids, edges with two equivalent O(4)Gd3Nb tetrahedra,  an edgeedge with one S(2)Gd4Nb trigonal bipyramid, and  an edgeedge with one O(1)Gd3Nb trigonal pyramid. There are four inequivalent O sites. In the first O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Gd(1), one Gd(2), and one Nb(1) atom. In the second O site, O(3) is bonded in a 3-coordinate geometry to one Gd(1), two equivalent Gd(3), and one Nb(1) atom. In the third O site, O(4) is bonded to one Gd(1), one Gd(2), one Gd(3), and one Nb(1) atom to form OGd3Nb tetrahedra that share  a cornercorner with one S(2)Gd4Nb trigonal bipyramid,  a cornercorner with one S(3)Gd4Nb trigonal bipyramid, corners with two equivalent O(1)Gd3Nb trigonal pyramids, edges with two equivalent S(2)Gd4Nb trigonal bipyramids, edges with two equivalent S(3)Gd4Nb trigonal bipyramids, and  an edgeedge with one O(1)Gd3Nb trigonal pyramid. In the fourth O site, O(1) is bonded to one Gd(1), one Gd(2), one Gd(3), and one Nb(1) atom to form distorted OGd3Nb trigonal pyramids that share corners with two equivalent O(4)Gd3Nb tetrahedra, corners with three equivalent S(3)Gd4Nb trigonal bipyramids, corners with five equivalent S(2)Gd4Nb trigonal bipyramids,  an edgeedge with one O(4)Gd3Nb tetrahedra, and  an edgeedge with one S(3)Gd4Nb trigonal bipyramid.