Rb3FeF6 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to four equivalent F(1) and four equivalent F(2) atoms to form distorted RbF8 hexagonal bipyramids that share corners with four equivalent Rb(1)F8 hexagonal bipyramids, edges with six equivalent Rb(1)F8 hexagonal bipyramids, and edges with four equivalent Fe(1)F6 octahedra. In the second Rb site, Rb(2) is bonded in a linear geometry to two equivalent F(2) atoms. Fe(1) is bonded to two equivalent F(2) and four equivalent F(1) atoms to form FeF6 octahedra that share edges with eight equivalent Rb(1)F8 hexagonal bipyramids. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to two equivalent Rb(1) and one Fe(1) atom. In the second F site, F(2) is bonded in a 6-coordinate geometry to one Rb(2), four equivalent Rb(1), and one Fe(1) atom.
Rb3FeF6 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to four equivalent F(1) and four equivalent F(2) atoms to form distorted RbF8 hexagonal bipyramids that share corners with four equivalent Rb(1)F8 hexagonal bipyramids, edges with six equivalent Rb(1)F8 hexagonal bipyramids, and edges with four equivalent Fe(1)F6 octahedra. All Rb(1)-F(1) bond lengths are 2.73 Å. All Rb(1)-F(2) bond lengths are 3.30 Å. In the second Rb site, Rb(2) is bonded in a linear geometry to two equivalent F(2) atoms. Both Rb(2)-F(2) bond lengths are 2.72 Å. Fe(1) is bonded to two equivalent F(2) and four equivalent F(1) atoms to form FeF6 octahedra that share edges with eight equivalent Rb(1)F8 hexagonal bipyramids. Both Fe(1)-F(2) bond lengths are 2.04 Å. All Fe(1)-F(1) bond lengths are 1.94 Å. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to two equivalent Rb(1) and one Fe(1) atom. In the second F site, F(2) is bonded in a 6-coordinate geometry to one Rb(2), four equivalent Rb(1), and one Fe(1) atom.