Rb2TaF7 crystallizes in the orthorhombic Pmmn space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 6-coordinate geometry to two equivalent F(3) and four equivalent F(1) atoms. In the second Rb site, Rb(2) is bonded to four equivalent F(2) and eight equivalent F(1) atoms to form RbF12 cuboctahedra that share corners with four equivalent Rb(2)F12 cuboctahedra, faces with four equivalent Rb(2)F12 cuboctahedra, and faces with four equivalent Ta(1)F7 pentagonal bipyramids. Ta(1) is bonded to one F(2), two equivalent F(3), and four equivalent F(1) atoms to form distorted TaF7 pentagonal bipyramids that share faces with four equivalent Rb(2)F12 cuboctahedra. There are three inequivalent F sites. In the first F site, F(1) is bonded in a distorted single-bond geometry to one Rb(1), two equivalent Rb(2), and one Ta(1) atom. In the second F site, F(2) is bonded in a distorted single-bond geometry to four equivalent Rb(2) and one Ta(1) atom. In the third F site, F(3) is bonded in a 1-coordinate geometry to one Rb(1) and one Ta(1) atom.
Rb2TaF7 crystallizes in the orthorhombic Pmmn space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 6-coordinate geometry to two equivalent F(3) and four equivalent F(1) atoms. Both Rb(1)-F(3) bond lengths are 2.83 Å. All Rb(1)-F(1) bond lengths are 2.80 Å. In the second Rb site, Rb(2) is bonded to four equivalent F(2) and eight equivalent F(1) atoms to form RbF12 cuboctahedra that share corners with four equivalent Rb(2)F12 cuboctahedra, faces with four equivalent Rb(2)F12 cuboctahedra, and faces with four equivalent Ta(1)F7 pentagonal bipyramids. There are two shorter (2.97 Å) and two longer (2.98 Å) Rb(2)-F(2) bond lengths. There are four shorter (2.92 Å) and four longer (3.01 Å) Rb(2)-F(1) bond lengths. Ta(1) is bonded to one F(2), two equivalent F(3), and four equivalent F(1) atoms to form distorted TaF7 pentagonal bipyramids that share faces with four equivalent Rb(2)F12 cuboctahedra. The Ta(1)-F(2) bond length is 2.02 Å. Both Ta(1)-F(3) bond lengths are 1.96 Å. All Ta(1)-F(1) bond lengths are 1.96 Å. There are three inequivalent F sites. In the first F site, F(1) is bonded in a distorted single-bond geometry to one Rb(1), two equivalent Rb(2), and one Ta(1) atom. In the second F site, F(2) is bonded in a distorted single-bond geometry to four equivalent Rb(2) and one Ta(1) atom. In the third F site, F(3) is bonded in a 1-coordinate geometry to one Rb(1) and one Ta(1) atom.