Sr2TbNbO6 is Orthorhombic Perovskite-derived structured and crystallizes in the cubic Pn-3 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to twelve equivalent O(1) atoms to form SrO12 cuboctahedra that share faces with four equivalent Tb(1)O6 octahedra and faces with four equivalent Nb(1)O6 octahedra. In the second Sr site, Sr(2) is bonded in a distorted square co-planar geometry to eight equivalent O(1) atoms. Tb(1) is bonded to six equivalent O(1) atoms to form TbO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra and faces with two equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 23°. Nb(1) is bonded to six equivalent O(1) atoms to form NbO6 octahedra that share corners with six equivalent Tb(1)O6 octahedra and faces with two equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 23°. O(1) is bonded in a 5-coordinate geometry to one Sr(1), two equivalent Sr(2), one Tb(1), and one Nb(1) atom.
Sr2TbNbO6 is Orthorhombic Perovskite-derived structured and crystallizes in the cubic Pn-3 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to twelve equivalent O(1) atoms to form SrO12 cuboctahedra that share faces with four equivalent Tb(1)O6 octahedra and faces with four equivalent Nb(1)O6 octahedra. All Sr(1)-O(1) bond lengths are 2.96 Å. In the second Sr site, Sr(2) is bonded in a distorted square co-planar geometry to eight equivalent O(1) atoms. There are four shorter (2.54 Å) and four longer (3.04 Å) Sr(2)-O(1) bond lengths. Tb(1) is bonded to six equivalent O(1) atoms to form TbO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra and faces with two equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 23°. All Tb(1)-O(1) bond lengths are 2.26 Å. Nb(1) is bonded to six equivalent O(1) atoms to form NbO6 octahedra that share corners with six equivalent Tb(1)O6 octahedra and faces with two equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 23°. All Nb(1)-O(1) bond lengths are 2.02 Å. O(1) is bonded in a 5-coordinate geometry to one Sr(1), two equivalent Sr(2), one Tb(1), and one Nb(1) atom.