Rb3GeF7 crystallizes in the tetragonal P4/mbm space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 10-coordinate geometry to two equivalent F(2), two equivalent F(3), and six equivalent F(1) atoms. In the second Rb site, Rb(2) is bonded to two equivalent F(3) and four equivalent F(2) atoms to form RbF6 octahedra that share corners with four equivalent Ge(1)F6 octahedra and corners with six equivalent Rb(2)F6 octahedra. The corner-sharing octahedral tilt angles range from 0-70°. Ge(1) is bonded to two equivalent F(2) and four equivalent F(1) atoms to form GeF6 octahedra that share corners with four equivalent Rb(2)F6 octahedra. The corner-sharing octahedral tilt angles are 70°. There are three inequivalent F sites. In the first F site, F(1) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one Ge(1) atom. In the second F site, F(2) is bonded in a distorted single-bond geometry to two equivalent Rb(1), two equivalent Rb(2), and one Ge(1) atom. In the third F site, F(3) is bonded to two equivalent Rb(2) and four equivalent Rb(1) atoms to form corner-sharing FRb6 octahedra. The corner-sharing octahedral tilt angles range from 0-26°.
Rb3GeF7 crystallizes in the tetragonal P4/mbm space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 10-coordinate geometry to two equivalent F(2), two equivalent F(3), and six equivalent F(1) atoms. Both Rb(1)-F(2) bond lengths are 2.96 Å. Both Rb(1)-F(3) bond lengths are 2.91 Å. There are two shorter (2.77 Å) and four longer (3.00 Å) Rb(1)-F(1) bond lengths. In the second Rb site, Rb(2) is bonded to two equivalent F(3) and four equivalent F(2) atoms to form RbF6 octahedra that share corners with four equivalent Ge(1)F6 octahedra and corners with six equivalent Rb(2)F6 octahedra. The corner-sharing octahedral tilt angles range from 0-70°. Both Rb(2)-F(3) bond lengths are 2.94 Å. All Rb(2)-F(2) bond lengths are 3.01 Å. Ge(1) is bonded to two equivalent F(2) and four equivalent F(1) atoms to form GeF6 octahedra that share corners with four equivalent Rb(2)F6 octahedra. The corner-sharing octahedral tilt angles are 70°. Both Ge(1)-F(2) bond lengths are 1.81 Å. All Ge(1)-F(1) bond lengths are 1.81 Å. There are three inequivalent F sites. In the first F site, F(1) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one Ge(1) atom. In the second F site, F(2) is bonded in a distorted single-bond geometry to two equivalent Rb(1), two equivalent Rb(2), and one Ge(1) atom. In the third F site, F(3) is bonded to two equivalent Rb(2) and four equivalent Rb(1) atoms to form corner-sharing FRb6 octahedra. The corner-sharing octahedral tilt angles range from 0-26°.