RbTaO3 crystallizes in the triclinic P-1 space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 2-coordinate geometry to two equivalent Rb(3) and two equivalent O(4) atoms. In the second Rb site, Rb(2) is bonded in a 2-coordinate geometry to one O(2) and one O(5) atom. In the third Rb site, Rb(3) is bonded to two equivalent Rb(1), two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms to form distorted corner-sharing RbRb2O6 hexagonal bipyramids. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 1-coordinate geometry to one O(1), one O(2), one O(3), and one O(5) atom. In the second Ta site, Ta(2) is bonded in a 3-coordinate geometry to one O(1), one O(2), one O(4), and one O(6) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ta(1), one Ta(2), and one O(6) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Rb(2), one Ta(1), and one Ta(2) atom. In the third O site, O(3) is bonded in a single-bond geometry to one Rb(3) and one Ta(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(3), and one Ta(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Rb(2) and one Ta(1) atom. In the sixth O site, O(6) is bonded in a 1-coordinate geometry to one Rb(3), one Ta(2), and one O(1) atom.
RbTaO3 crystallizes in the triclinic P-1 space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 2-coordinate geometry to two equivalent Rb(3) and two equivalent O(4) atoms. Both Rb(1)-Rb(3) bond lengths are 2.59 Å. Both Rb(1)-O(4) bond lengths are 3.19 Å. In the second Rb site, Rb(2) is bonded in a 2-coordinate geometry to one O(2) and one O(5) atom. The Rb(2)-O(2) bond length is 2.28 Å. The Rb(2)-O(5) bond length is 2.37 Å. In the third Rb site, Rb(3) is bonded to two equivalent Rb(1), two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms to form distorted corner-sharing RbRb2O6 hexagonal bipyramids. Both Rb(3)-O(3) bond lengths are 3.55 Å. Both Rb(3)-O(4) bond lengths are 3.05 Å. Both Rb(3)-O(6) bond lengths are 3.39 Å. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 1-coordinate geometry to one O(1), one O(2), one O(3), and one O(5) atom. The Ta(1)-O(1) bond length is 2.40 Å. The Ta(1)-O(2) bond length is 2.22 Å. The Ta(1)-O(3) bond length is 1.74 Å. The Ta(1)-O(5) bond length is 2.23 Å. In the second Ta site, Ta(2) is bonded in a 3-coordinate geometry to one O(1), one O(2), one O(4), and one O(6) atom. The Ta(2)-O(1) bond length is 2.65 Å. The Ta(2)-O(2) bond length is 2.05 Å. The Ta(2)-O(4) bond length is 1.90 Å. The Ta(2)-O(6) bond length is 2.29 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ta(1), one Ta(2), and one O(6) atom. The O(1)-O(6) bond length is 1.78 Å. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Rb(2), one Ta(1), and one Ta(2) atom. In the third O site, O(3) is bonded in a single-bond geometry to one Rb(3) and one Ta(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(3), and one Ta(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Rb(2) and one Ta(1) atom. In the sixth O site, O(6) is bonded in a 1-coordinate geometry to one Rb(3), one Ta(2), and one O(1) atom.