CsMgCl3 crystallizes in the hexagonal P6_3/mmc space group. Cs(1) is bonded to twelve equivalent Cl(1) atoms to form CsCl12 cuboctahedra that share corners with six equivalent Cs(1)Cl12 cuboctahedra, corners with six equivalent Mg(1)Cl6 octahedra, faces with eight equivalent Cs(1)Cl12 cuboctahedra, and faces with six equivalent Mg(1)Cl6 octahedra. The corner-sharing octahedral tilt angles are 16°. Mg(1) is bonded to six equivalent Cl(1) atoms to form MgCl6 octahedra that share corners with six equivalent Cs(1)Cl12 cuboctahedra, faces with six equivalent Cs(1)Cl12 cuboctahedra, and faces with two equivalent Mg(1)Cl6 octahedra. Cl(1) is bonded in a 2-coordinate geometry to four equivalent Cs(1) and two equivalent Mg(1) atoms.
CsMgCl3 crystallizes in the hexagonal P6_3/mmc space group. Cs(1) is bonded to twelve equivalent Cl(1) atoms to form CsCl12 cuboctahedra that share corners with six equivalent Cs(1)Cl12 cuboctahedra, corners with six equivalent Mg(1)Cl6 octahedra, faces with eight equivalent Cs(1)Cl12 cuboctahedra, and faces with six equivalent Mg(1)Cl6 octahedra. The corner-sharing octahedral tilt angles are 16°. There are six shorter (3.65 Å) and six longer (3.82 Å) Cs(1)-Cl(1) bond lengths. Mg(1) is bonded to six equivalent Cl(1) atoms to form MgCl6 octahedra that share corners with six equivalent Cs(1)Cl12 cuboctahedra, faces with six equivalent Cs(1)Cl12 cuboctahedra, and faces with two equivalent Mg(1)Cl6 octahedra. All Mg(1)-Cl(1) bond lengths are 2.50 Å. Cl(1) is bonded in a 2-coordinate geometry to four equivalent Cs(1) and two equivalent Mg(1) atoms.