TbNbO4 crystallizes in the monoclinic P2_1/c space group. Tb(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), three equivalent O(3), and three equivalent O(4) atoms. Nb(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 38-50°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Tb(1) and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Tb(1) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to three equivalent Tb(1) and one Nb(1) atom. In the fourth O site, O(4) is bonded to three equivalent Tb(1) and one Nb(1) atom to form a mixture of distorted corner and edge-sharing OTb3Nb tetrahedra.
TbNbO4 crystallizes in the monoclinic P2_1/c space group. Tb(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), three equivalent O(3), and three equivalent O(4) atoms. The Tb(1)-O(1) bond length is 2.55 Å. The Tb(1)-O(2) bond length is 2.33 Å. There are a spread of Tb(1)-O(3) bond distances ranging from 2.30-2.84 Å. There are a spread of Tb(1)-O(4) bond distances ranging from 2.24-2.53 Å. Nb(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 38-50°. The Nb(1)-O(3) bond length is 1.93 Å. The Nb(1)-O(4) bond length is 2.08 Å. There is one shorter (1.97 Å) and one longer (2.12 Å) Nb(1)-O(1) bond length. There is one shorter (2.00 Å) and one longer (2.06 Å) Nb(1)-O(2) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Tb(1) and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Tb(1) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to three equivalent Tb(1) and one Nb(1) atom. In the fourth O site, O(4) is bonded to three equivalent Tb(1) and one Nb(1) atom to form a mixture of distorted corner and edge-sharing OTb3Nb tetrahedra.