GdSbO4 crystallizes in the triclinic P-1 space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(5), one O(6), one O(7), and two equivalent O(8) atoms. In the second Gd site, Gd(2) is bonded to one O(3), one O(4), one O(6), one O(7), one O(8), and two equivalent O(5) atoms to form distorted GdO7 pentagonal bipyramids that share corners with three equivalent Sb(1)O6 octahedra,  an edgeedge with one Sb(1)O6 octahedra, edges with two equivalent Sb(2)O6 octahedra, and  an edgeedge with one Gd(2)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 30-64°. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form distorted SbO6 octahedra that share corners with two equivalent Sb(2)O6 octahedra, corners with three equivalent Gd(2)O7 pentagonal bipyramids,  an edgeedge with one Sb(2)O6 octahedra, and  an edgeedge with one Gd(2)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 34-51°. In the second Sb site, Sb(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(8) atom to form SbO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra,  an edgeedge with one Sb(1)O6 octahedra, and edges with two equivalent Gd(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 34-51°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Gd(1), one Sb(1), and one Sb(2) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Gd(1), one Sb(1), and one Sb(2) atom. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to one Gd(2), one Sb(1), and one Sb(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Gd(2), one Sb(1), and one Sb(2) atom. In the fifth O site, O(5) is bonded to one Gd(1), two equivalent Gd(2), and one Sb(1) atom to form a mixture of edge and corner-sharing OGd3Sb tetrahedra. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Gd(1), one Gd(2), and one Sb(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Gd(1), one Gd(2), and one Sb(1) atom. In the eighth O site, O(8) is bonded to one Gd(2), two equivalent Gd(1), and one Sb(2) atom to form a mixture of distorted edge and corner-sharing OGd3Sb tetrahedra.
GdSbO4 crystallizes in the triclinic P-1 space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(5), one O(6), one O(7), and two equivalent O(8) atoms. The Gd(1)-O(1) bond length is 2.34 Å. The Gd(1)-O(2) bond length is 2.34 Å. The Gd(1)-O(5) bond length is 2.37 Å. The Gd(1)-O(6) bond length is 2.28 Å. The Gd(1)-O(7) bond length is 2.53 Å. There is one shorter (2.34 Å) and one longer (2.42 Å) Gd(1)-O(8) bond length. In the second Gd site, Gd(2) is bonded to one O(3), one O(4), one O(6), one O(7), one O(8), and two equivalent O(5) atoms to form distorted GdO7 pentagonal bipyramids that share corners with three equivalent Sb(1)O6 octahedra,  an edgeedge with one Sb(1)O6 octahedra, edges with two equivalent Sb(2)O6 octahedra, and  an edgeedge with one Gd(2)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 30-64°. The Gd(2)-O(3) bond length is 2.39 Å. The Gd(2)-O(4) bond length is 2.37 Å. The Gd(2)-O(6) bond length is 2.25 Å. The Gd(2)-O(7) bond length is 2.27 Å. The Gd(2)-O(8) bond length is 2.57 Å. There is one shorter (2.46 Å) and one longer (2.50 Å) Gd(2)-O(5) bond length. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form distorted SbO6 octahedra that share corners with two equivalent Sb(2)O6 octahedra, corners with three equivalent Gd(2)O7 pentagonal bipyramids,  an edgeedge with one Sb(2)O6 octahedra, and  an edgeedge with one Gd(2)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 34-51°. The Sb(1)-O(1) bond length is 2.08 Å. The Sb(1)-O(2) bond length is 2.07 Å. The Sb(1)-O(3) bond length is 2.15 Å. The Sb(1)-O(4) bond length is 2.04 Å. The Sb(1)-O(5) bond length is 2.06 Å. The Sb(1)-O(7) bond length is 1.96 Å. In the second Sb site, Sb(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(8) atom to form SbO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra,  an edgeedge with one Sb(1)O6 octahedra, and edges with two equivalent Gd(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 34-51°. The Sb(2)-O(1) bond length is 2.00 Å. The Sb(2)-O(2) bond length is 2.02 Å. The Sb(2)-O(3) bond length is 2.06 Å. The Sb(2)-O(4) bond length is 2.06 Å. The Sb(2)-O(6) bond length is 1.98 Å. The Sb(2)-O(8) bond length is 2.04 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Gd(1), one Sb(1), and one Sb(2) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Gd(1), one Sb(1), and one Sb(2) atom. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to one Gd(2), one Sb(1), and one Sb(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Gd(2), one Sb(1), and one Sb(2) atom. In the fifth O site, O(5) is bonded to one Gd(1), two equivalent Gd(2), and one Sb(1) atom to form a mixture of edge and corner-sharing OGd3Sb tetrahedra. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Gd(1), one Gd(2), and one Sb(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Gd(1), one Gd(2), and one Sb(1) atom. In the eighth O site, O(8) is bonded to one Gd(2), two equivalent Gd(1), and one Sb(2) atom to form a mixture of distorted edge and corner-sharing OGd3Sb tetrahedra.