Rb2Zr2O5 crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to eight equivalent O(1) atoms to form distorted RbO8 hexagonal bipyramids that share corners with eight equivalent Rb(2)O12 cuboctahedra, edges with four equivalent Rb(1)O8 hexagonal bipyramids, edges with eight equivalent Zr(1)O5 square pyramids, and faces with two equivalent Rb(2)O12 cuboctahedra. In the second Rb site, Rb(2) is bonded to four equivalent O(2) and eight equivalent O(1) atoms to form RbO12 cuboctahedra that share corners with four equivalent Rb(2)O12 cuboctahedra, corners with eight equivalent Rb(1)O8 hexagonal bipyramids, faces with four equivalent Rb(2)O12 cuboctahedra, faces with two equivalent Rb(1)O8 hexagonal bipyramids, and faces with eight equivalent Zr(1)O5 square pyramids. Zr(1) is bonded to one O(2) and four equivalent O(1) atoms to form distorted ZrO5 square pyramids that share corners with five equivalent Zr(1)O5 square pyramids, edges with four equivalent Rb(1)O8 hexagonal bipyramids, and faces with four equivalent Rb(2)O12 cuboctahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), and two equivalent Zr(1) atoms. In the second O site, O(2) is bonded to four equivalent Rb(2) and two equivalent Zr(1) atoms to form a mixture of distorted edge and corner-sharing ORb4Zr2 octahedra. The corner-sharing octahedra are not tilted.
Rb2Zr2O5 crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to eight equivalent O(1) atoms to form distorted RbO8 hexagonal bipyramids that share corners with eight equivalent Rb(2)O12 cuboctahedra, edges with four equivalent Rb(1)O8 hexagonal bipyramids, edges with eight equivalent Zr(1)O5 square pyramids, and faces with two equivalent Rb(2)O12 cuboctahedra. All Rb(1)-O(1) bond lengths are 2.96 Å. In the second Rb site, Rb(2) is bonded to four equivalent O(2) and eight equivalent O(1) atoms to form RbO12 cuboctahedra that share corners with four equivalent Rb(2)O12 cuboctahedra, corners with eight equivalent Rb(1)O8 hexagonal bipyramids, faces with four equivalent Rb(2)O12 cuboctahedra, faces with two equivalent Rb(1)O8 hexagonal bipyramids, and faces with eight equivalent Zr(1)O5 square pyramids. All Rb(2)-O(2) bond lengths are 2.91 Å. All Rb(2)-O(1) bond lengths are 3.21 Å. Zr(1) is bonded to one O(2) and four equivalent O(1) atoms to form distorted ZrO5 square pyramids that share corners with five equivalent Zr(1)O5 square pyramids, edges with four equivalent Rb(1)O8 hexagonal bipyramids, and faces with four equivalent Rb(2)O12 cuboctahedra. The Zr(1)-O(2) bond length is 2.05 Å. All Zr(1)-O(1) bond lengths are 2.10 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), and two equivalent Zr(1) atoms. In the second O site, O(2) is bonded to four equivalent Rb(2) and two equivalent Zr(1) atoms to form a mixture of distorted edge and corner-sharing ORb4Zr2 octahedra. The corner-sharing octahedra are not tilted.