RbK2TiF6 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal I4/mmm space group. Rb(1) is bonded to two equivalent F(2) and four equivalent F(1) atoms to form RbF6 octahedra that share corners with six equivalent Ti(1)F6 octahedra and faces with eight equivalent K(1)F12 cuboctahedra. The corner-sharing octahedra are not tilted. K(1) is bonded to four equivalent F(2) and eight equivalent F(1) atoms to form distorted KF12 cuboctahedra that share corners with twelve equivalent K(1)F12 cuboctahedra, faces with six equivalent K(1)F12 cuboctahedra, faces with four equivalent Rb(1)F6 octahedra, and faces with four equivalent Ti(1)F6 octahedra. Ti(1) is bonded to two equivalent F(2) and four equivalent F(1) atoms to form TiF6 octahedra that share corners with six equivalent Rb(1)F6 octahedra and faces with eight equivalent K(1)F12 cuboctahedra. The corner-sharing octahedra are not tilted. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted linear geometry to one Rb(1), four equivalent K(1), and one Ti(1) atom. In the second F site, F(2) is bonded in a distorted linear geometry to one Rb(1), four equivalent K(1), and one Ti(1) atom.
RbK2TiF6 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal I4/mmm space group. Rb(1) is bonded to two equivalent F(2) and four equivalent F(1) atoms to form RbF6 octahedra that share corners with six equivalent Ti(1)F6 octahedra and faces with eight equivalent K(1)F12 cuboctahedra. The corner-sharing octahedra are not tilted. Both Rb(1)-F(2) bond lengths are 2.58 Å. All Rb(1)-F(1) bond lengths are 2.58 Å. K(1) is bonded to four equivalent F(2) and eight equivalent F(1) atoms to form distorted KF12 cuboctahedra that share corners with twelve equivalent K(1)F12 cuboctahedra, faces with six equivalent K(1)F12 cuboctahedra, faces with four equivalent Rb(1)F6 octahedra, and faces with four equivalent Ti(1)F6 octahedra. All K(1)-F(2) bond lengths are 3.25 Å. All K(1)-F(1) bond lengths are 3.22 Å. Ti(1) is bonded to two equivalent F(2) and four equivalent F(1) atoms to form TiF6 octahedra that share corners with six equivalent Rb(1)F6 octahedra and faces with eight equivalent K(1)F12 cuboctahedra. The corner-sharing octahedra are not tilted. Both Ti(1)-F(2) bond lengths are 1.92 Å. All Ti(1)-F(1) bond lengths are 1.99 Å. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted linear geometry to one Rb(1), four equivalent K(1), and one Ti(1) atom. In the second F site, F(2) is bonded in a distorted linear geometry to one Rb(1), four equivalent K(1), and one Ti(1) atom.