SbNbO4 crystallizes in the orthorhombic Pna2_1 space group. Nb(1) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form distorted NbO6 octahedra that share corners with four equivalent Nb(1)O6 octahedra, corners with four equivalent Sb(1)O5 square pyramids, and  an edgeedge with one Sb(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 29-53°. Sb(1) is bonded to one O(4), two equivalent O(2), and two equivalent O(3) atoms to form distorted SbO5 square pyramids that share corners with four equivalent Nb(1)O6 octahedra,  an edgeedge with one Nb(1)O6 octahedra, and edges with two equivalent Sb(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 43-57°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Nb(1) and two equivalent Sb(1) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Nb(1) and two equivalent Sb(1) atoms. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Nb(1) and one Sb(1) atom.
SbNbO4 crystallizes in the orthorhombic Pna2_1 space group. Nb(1) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form distorted NbO6 octahedra that share corners with four equivalent Nb(1)O6 octahedra, corners with four equivalent Sb(1)O5 square pyramids, and  an edgeedge with one Sb(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 29-53°. The Nb(1)-O(2) bond length is 2.15 Å. The Nb(1)-O(3) bond length is 1.96 Å. There is one shorter (1.86 Å) and one longer (2.10 Å) Nb(1)-O(1) bond length. There is one shorter (1.92 Å) and one longer (2.15 Å) Nb(1)-O(4) bond length. Sb(1) is bonded to one O(4), two equivalent O(2), and two equivalent O(3) atoms to form distorted SbO5 square pyramids that share corners with four equivalent Nb(1)O6 octahedra,  an edgeedge with one Nb(1)O6 octahedra, and edges with two equivalent Sb(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 43-57°. The Sb(1)-O(4) bond length is 2.49 Å. There is one shorter (2.02 Å) and one longer (2.10 Å) Sb(1)-O(2) bond length. There is one shorter (2.04 Å) and one longer (2.43 Å) Sb(1)-O(3) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Nb(1) and two equivalent Sb(1) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Nb(1) and two equivalent Sb(1) atoms. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Nb(1) and one Sb(1) atom.