(Rb2Cl)LaNb2O7 crystallizes in the tetragonal P4/mmm space group. Rb(1) is bonded in a distorted body-centered cubic geometry to four equivalent O(2) and four equivalent Cl(1) atoms. La(1) is bonded to four equivalent O(3) and eight equivalent O(1) atoms to form a mixture of face and corner-sharing LaO12 cuboctahedra. Nb(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), and four equivalent O(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent La(1) and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a distorted single-bond geometry to four equivalent Rb(1) and one Nb(1) atom. In the third O site, O(3) is bonded to four equivalent La(1) and two equivalent Nb(1) atoms to form a mixture of corner and edge-sharing OLa4Nb2 octahedra. The corner-sharing octahedra are not tilted. Cl(1) is bonded in a body-centered cubic geometry to eight equivalent Rb(1) atoms.
(Rb2Cl)LaNb2O7 crystallizes in the tetragonal P4/mmm space group. Rb(1) is bonded in a distorted body-centered cubic geometry to four equivalent O(2) and four equivalent Cl(1) atoms. All Rb(1)-O(2) bond lengths are 3.13 Å. All Rb(1)-Cl(1) bond lengths are 3.44 Å. La(1) is bonded to four equivalent O(3) and eight equivalent O(1) atoms to form a mixture of face and corner-sharing LaO12 cuboctahedra. All La(1)-O(3) bond lengths are 2.78 Å. All La(1)-O(1) bond lengths are 2.72 Å. Nb(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), and four equivalent O(1) atoms. The Nb(1)-O(2) bond length is 1.81 Å. The Nb(1)-O(3) bond length is 2.32 Å. All Nb(1)-O(1) bond lengths are 2.01 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent La(1) and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a distorted single-bond geometry to four equivalent Rb(1) and one Nb(1) atom. In the third O site, O(3) is bonded to four equivalent La(1) and two equivalent Nb(1) atoms to form a mixture of corner and edge-sharing OLa4Nb2 octahedra. The corner-sharing octahedra are not tilted. Cl(1) is bonded in a body-centered cubic geometry to eight equivalent Rb(1) atoms.