Rb2LaNb5O15 crystallizes in the tetragonal P4/mbm space group. Rb(1) is bonded in a 9-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and four equivalent O(5) atoms. La(1) is bonded to four equivalent O(1) and eight equivalent O(4) atoms to form LaO12 cuboctahedra that share faces with two equivalent La(1)O12 cuboctahedra and faces with eight equivalent Nb(2)O6 octahedra. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(3) and four equivalent O(5) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 0-31°. In the second Nb site, Nb(2) is bonded to one O(2), one O(5), two equivalent O(1), and two equivalent O(4) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra, corners with five equivalent Nb(2)O6 octahedra, and faces with two equivalent La(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 10-34°. There are five inequivalent O sites. In the first O site, O(5) is bonded in a distorted bent 150 degrees geometry to two equivalent Rb(1), one Nb(1), and one Nb(2) atom. In the second O site, O(1) is bonded in a 2-coordinate geometry to one Rb(1), one La(1), and two equivalent Nb(2) atoms. In the third O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Rb(1) and two equivalent Nb(2) atoms. In the fourth O site, O(3) is bonded in a linear geometry to two equivalent Rb(1) and two equivalent Nb(1) atoms. In the fifth O site, O(4) is bonded in a 2-coordinate geometry to two equivalent La(1) and two equivalent Nb(2) atoms.
Rb2LaNb5O15 crystallizes in the tetragonal P4/mbm space group. Rb(1) is bonded in a 9-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and four equivalent O(5) atoms. The Rb(1)-O(3) bond length is 3.11 Å. Both Rb(1)-O(1) bond lengths are 3.21 Å. Both Rb(1)-O(2) bond lengths are 2.87 Å. All Rb(1)-O(5) bond lengths are 2.96 Å. La(1) is bonded to four equivalent O(1) and eight equivalent O(4) atoms to form LaO12 cuboctahedra that share faces with two equivalent La(1)O12 cuboctahedra and faces with eight equivalent Nb(2)O6 octahedra. All La(1)-O(1) bond lengths are 2.65 Å. All La(1)-O(4) bond lengths are 2.72 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(3) and four equivalent O(5) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 0-31°. Both Nb(1)-O(3) bond lengths are 1.98 Å. All Nb(1)-O(5) bond lengths are 2.00 Å. In the second Nb site, Nb(2) is bonded to one O(2), one O(5), two equivalent O(1), and two equivalent O(4) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra, corners with five equivalent Nb(2)O6 octahedra, and faces with two equivalent La(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 10-34°. The Nb(2)-O(2) bond length is 1.99 Å. The Nb(2)-O(5) bond length is 1.91 Å. Both Nb(2)-O(1) bond lengths are 2.00 Å. There is one shorter (2.03 Å) and one longer (2.10 Å) Nb(2)-O(4) bond length. There are five inequivalent O sites. In the first O site, O(5) is bonded in a distorted bent 150 degrees geometry to two equivalent Rb(1), one Nb(1), and one Nb(2) atom. In the second O site, O(1) is bonded in a 2-coordinate geometry to one Rb(1), one La(1), and two equivalent Nb(2) atoms. In the third O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Rb(1) and two equivalent Nb(2) atoms. In the fourth O site, O(3) is bonded in a linear geometry to two equivalent Rb(1) and two equivalent Nb(1) atoms. In the fifth O site, O(4) is bonded in a 2-coordinate geometry to two equivalent La(1) and two equivalent Nb(2) atoms.