CsKMg6 crystallizes in the monoclinic Pm space group. Cs(1) is bonded in a 10-coordinate geometry to two equivalent K(1), one Mg(1), one Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Mg(6) atoms. K(1) is bonded to two equivalent Cs(1), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Mg(5) atoms to form a mixture of distorted corner and face-sharing KCs2Mg6 hexagonal bipyramids. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 9-coordinate geometry to one Cs(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(5), and two equivalent Mg(6) atoms. In the second Mg site, Mg(2) is bonded in a 9-coordinate geometry to one Cs(1), two equivalent Mg(1), two equivalent Mg(4), two equivalent Mg(5), and two equivalent Mg(6) atoms. In the third Mg site, Mg(3) is bonded in a 10-coordinate geometry to two equivalent Cs(1), two equivalent K(1), one Mg(5), one Mg(6), two equivalent Mg(1), and two equivalent Mg(4) atoms. In the fourth Mg site, Mg(4) is bonded in a 10-coordinate geometry to two equivalent Cs(1), two equivalent K(1), one Mg(5), one Mg(6), two equivalent Mg(2), and two equivalent Mg(3) atoms. In the fifth Mg site, Mg(5) is bonded in a 10-coordinate geometry to two equivalent K(1), one Mg(3), one Mg(4), two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mg(6) atoms. In the sixth Mg site, Mg(6) is bonded in a 10-coordinate geometry to two equivalent Cs(1), one Mg(3), one Mg(4), two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mg(5) atoms.
CsKMg6 crystallizes in the monoclinic Pm space group. Cs(1) is bonded in a 10-coordinate geometry to two equivalent K(1), one Mg(1), one Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Mg(6) atoms. There is one shorter (3.42 Å) and one longer (3.43 Å) Cs(1)-K(1) bond length. The Cs(1)-Mg(1) bond length is 4.23 Å. The Cs(1)-Mg(2) bond length is 4.17 Å. Both Cs(1)-Mg(3) bond lengths are 4.03 Å. Both Cs(1)-Mg(4) bond lengths are 3.99 Å. Both Cs(1)-Mg(6) bond lengths are 3.96 Å. K(1) is bonded to two equivalent Cs(1), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Mg(5) atoms to form a mixture of distorted corner and face-sharing KCs2Mg6 hexagonal bipyramids. Both K(1)-Mg(3) bond lengths are 3.88 Å. Both K(1)-Mg(4) bond lengths are 3.94 Å. Both K(1)-Mg(5) bond lengths are 3.98 Å. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 9-coordinate geometry to one Cs(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(5), and two equivalent Mg(6) atoms. There is one shorter (3.39 Å) and one longer (3.45 Å) Mg(1)-Mg(2) bond length. Both Mg(1)-Mg(3) bond lengths are 3.10 Å. Both Mg(1)-Mg(5) bond lengths are 3.18 Å. Both Mg(1)-Mg(6) bond lengths are 3.18 Å. In the second Mg site, Mg(2) is bonded in a 9-coordinate geometry to one Cs(1), two equivalent Mg(1), two equivalent Mg(4), two equivalent Mg(5), and two equivalent Mg(6) atoms. Both Mg(2)-Mg(4) bond lengths are 3.09 Å. Both Mg(2)-Mg(5) bond lengths are 3.20 Å. Both Mg(2)-Mg(6) bond lengths are 3.17 Å. In the third Mg site, Mg(3) is bonded in a 10-coordinate geometry to two equivalent Cs(1), two equivalent K(1), one Mg(5), one Mg(6), two equivalent Mg(1), and two equivalent Mg(4) atoms. The Mg(3)-Mg(5) bond length is 3.16 Å. The Mg(3)-Mg(6) bond length is 3.11 Å. There is one shorter (3.41 Å) and one longer (3.43 Å) Mg(3)-Mg(4) bond length. In the fourth Mg site, Mg(4) is bonded in a 10-coordinate geometry to two equivalent Cs(1), two equivalent K(1), one Mg(5), one Mg(6), two equivalent Mg(2), and two equivalent Mg(3) atoms. The Mg(4)-Mg(5) bond length is 3.21 Å. The Mg(4)-Mg(6) bond length is 3.04 Å. In the fifth Mg site, Mg(5) is bonded in a 10-coordinate geometry to two equivalent K(1), one Mg(3), one Mg(4), two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mg(6) atoms. There is one shorter (3.42 Å) and one longer (3.43 Å) Mg(5)-Mg(6) bond length. In the sixth Mg site, Mg(6) is bonded in a 10-coordinate geometry to two equivalent Cs(1), one Mg(3), one Mg(4), two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mg(5) atoms.