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 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second Rb site, Rb(2) is bonded in a 8-coordinate geometry to one O(2), one O(4), one O(5), two equivalent O(6), and three equivalent O(3) atoms. In the third Rb site, Rb(3) is bonded in a 6-coordinate geometry to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(5), one O(6), and two equivalent O(1) atoms. In the second Ta site, Ta(2) is bonded in a 6-coordinate geometry to one O(2), one O(4), one O(5), one O(6), and two equivalent O(1) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ta(1) and two equivalent Ta(2) atoms. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(2), one Ta(1), and one Ta(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Rb(1), three equivalent Rb(2), 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(2), one Rb(3), and one Ta(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Rb(2), one Rb(3), one Ta(1), and one Ta(2) atom. In the sixth O site, O(6) is bonded in a distorted water-like geometry to one Rb(3), two equivalent Rb(2), one Ta(1), and one Ta(2) 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 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. Both Rb(1)-O(2) bond lengths are 2.82 Å. Both Rb(1)-O(3) bond lengths are 3.35 Å. Both Rb(1)-O(4) bond lengths are 3.00 Å. In the second Rb site, Rb(2) is bonded in a 8-coordinate geometry to one O(2), one O(4), one O(5), two equivalent O(6), and three equivalent O(3) atoms. The Rb(2)-O(2) bond length is 3.33 Å. The Rb(2)-O(4) bond length is 2.83 Å. The Rb(2)-O(5) bond length is 3.09 Å. There is one shorter (3.04 Å) and one longer (3.32 Å) Rb(2)-O(6) bond length. There are a spread of Rb(2)-O(3) bond distances ranging from 2.85-3.02 Å. In the third Rb site, Rb(3) is bonded in a 6-coordinate geometry to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms. Both Rb(3)-O(4) bond lengths are 2.76 Å. Both Rb(3)-O(5) bond lengths are 2.78 Å. Both Rb(3)-O(6) bond lengths are 3.16 Å. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(5), one O(6), and two equivalent O(1) atoms. The Ta(1)-O(2) bond length is 1.98 Å. The Ta(1)-O(3) bond length is 1.80 Å. The Ta(1)-O(5) bond length is 2.03 Å. The Ta(1)-O(6) bond length is 1.93 Å. There is one shorter (2.07 Å) and one longer (2.40 Å) Ta(1)-O(1) bond length. In the second Ta site, Ta(2) is bonded in a 6-coordinate geometry to one O(2), one O(4), one O(5), one O(6), and two equivalent O(1) atoms. The Ta(2)-O(2) bond length is 1.96 Å. The Ta(2)-O(4) bond length is 1.80 Å. The Ta(2)-O(5) bond length is 1.92 Å. The Ta(2)-O(6) bond length is 2.04 Å. There is one shorter (2.06 Å) and one longer (2.48 Å) Ta(2)-O(1) bond length. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ta(1) and two equivalent Ta(2) atoms. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(2), one Ta(1), and one Ta(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Rb(1), three equivalent Rb(2), 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(2), one Rb(3), and one Ta(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Rb(2), one Rb(3), one Ta(1), and one Ta(2) atom. In the sixth O site, O(6) is bonded in a distorted water-like geometry to one Rb(3), two equivalent Rb(2), one Ta(1), and one Ta(2) atom.