RbMgF3 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 6-coordinate geometry to three equivalent F(1) and three equivalent F(2) atoms. In the second Rb site, Rb(2) is bonded in a 6-coordinate geometry to six equivalent F(2) atoms. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 3-coordinate geometry to three equivalent F(1) atoms. In the second Mg site, Mg(2) is bonded in an octahedral geometry to six equivalent F(2) atoms. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted L-shaped geometry to two equivalent Rb(1) and two equivalent Mg(1) atoms. In the second F site, F(2) is bonded in a 3-coordinate geometry to one Rb(1), one Rb(2), and one Mg(2) atom.
RbMgF3 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 6-coordinate geometry to three equivalent F(1) and three equivalent F(2) atoms. All Rb(1)-F(1) bond lengths are 2.99 Å. All Rb(1)-F(2) bond lengths are 2.50 Å. In the second Rb site, Rb(2) is bonded in a 6-coordinate geometry to six equivalent F(2) atoms. All Rb(2)-F(2) bond lengths are 2.87 Å. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 3-coordinate geometry to three equivalent F(1) atoms. All Mg(1)-F(1) bond lengths are 1.96 Å. In the second Mg site, Mg(2) is bonded in an octahedral geometry to six equivalent F(2) atoms. All Mg(2)-F(2) bond lengths are 2.02 Å. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted L-shaped geometry to two equivalent Rb(1) and two equivalent Mg(1) atoms. In the second F site, F(2) is bonded in a 3-coordinate geometry to one Rb(1), one Rb(2), and one Mg(2) atom.