Rb2Hf3OF12 crystallizes in the trigonal R-3m space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to six equivalent F(2) and six equivalent F(3) atoms to form face-sharing RbF12 cuboctahedra. In the second Rb site, Rb(2) is bonded to six equivalent F(4) atoms to form distorted corner-sharing RbF6 cuboctahedra. The corner-sharing octahedral tilt angles are 73°. In the third Rb site, Rb(3) is bonded to three equivalent F(2) and three equivalent F(4) atoms to form distorted RbF6 octahedra that share corners with three equivalent Rb(2)F6 cuboctahedra and  a faceface with one Rb(1)F12 cuboctahedra. Hf(1) is bonded in a 8-coordinate geometry to one O(1), one F(4), two equivalent F(1), two equivalent F(2), and two equivalent F(3) atoms. O(1) is bonded in a trigonal planar geometry to three equivalent Hf(1) atoms. There are four inequivalent F sites. In the first F site, F(1) is bonded in a bent 150 degrees geometry to two equivalent Hf(1) atoms. In the second F site, F(2) is bonded in a 4-coordinate geometry to one Rb(1), one Rb(3), and two equivalent Hf(1) atoms. In the third F site, F(3) is bonded in a trigonal planar geometry to one Rb(1) and two equivalent Hf(1) atoms. In the fourth F site, F(4) is bonded in a distorted single-bond geometry to one Rb(2), one Rb(3), and one Hf(1) atom.
Rb2Hf3OF12 crystallizes in the trigonal R-3m space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to six equivalent F(2) and six equivalent F(3) atoms to form face-sharing RbF12 cuboctahedra. All Rb(1)-F(2) bond lengths are 3.08 Å. All Rb(1)-F(3) bond lengths are 2.69 Å. In the second Rb site, Rb(2) is bonded to six equivalent F(4) atoms to form distorted corner-sharing RbF6 cuboctahedra. The corner-sharing octahedral tilt angles are 73°. All Rb(2)-F(4) bond lengths are 2.78 Å. In the third Rb site, Rb(3) is bonded to three equivalent F(2) and three equivalent F(4) atoms to form distorted RbF6 octahedra that share corners with three equivalent Rb(2)F6 cuboctahedra and  a faceface with one Rb(1)F12 cuboctahedra. All Rb(3)-F(2) bond lengths are 2.88 Å. All Rb(3)-F(4) bond lengths are 2.81 Å. Hf(1) is bonded in a 8-coordinate geometry to one O(1), one F(4), two equivalent F(1), two equivalent F(2), and two equivalent F(3) atoms. The Hf(1)-O(1) bond length is 2.05 Å. The Hf(1)-F(4) bond length is 1.97 Å. Both Hf(1)-F(1) bond lengths are 2.14 Å. Both Hf(1)-F(2) bond lengths are 2.18 Å. Both Hf(1)-F(3) bond lengths are 2.12 Å. O(1) is bonded in a trigonal planar geometry to three equivalent Hf(1) atoms. There are four inequivalent F sites. In the first F site, F(1) is bonded in a bent 150 degrees geometry to two equivalent Hf(1) atoms. In the second F site, F(2) is bonded in a 4-coordinate geometry to one Rb(1), one Rb(3), and two equivalent Hf(1) atoms. In the third F site, F(3) is bonded in a trigonal planar geometry to one Rb(1) and two equivalent Hf(1) atoms. In the fourth F site, F(4) is bonded in a distorted single-bond geometry to one Rb(2), one Rb(3), and one Hf(1) atom.