CsKMg6 crystallizes in the orthorhombic Amm2 space group. Cs(1) is bonded in a 10-coordinate geometry to two equivalent K(1); two Mg(1,1); two equivalent Mg(4); and four Mg(2,2) atoms. K(1) is bonded to two equivalent Cs(1); two equivalent Mg(3); and four Mg(2,2) atoms to form a mixture of distorted face and corner-sharing KCs2Mg6 hexagonal bipyramids. There are nine inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 9-coordinate geometry to one Cs(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms. In the second Mg site, Mg(1) is bonded in a 9-coordinate geometry to one Cs(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms. In the third Mg site, Mg(2) is bonded in a 10-coordinate geometry to two equivalent Cs(1), two equivalent K(1), one Mg(3), one Mg(4), two equivalent Mg(1), and two equivalent Mg(2) atoms. In the fourth Mg site, Mg(2) is bonded in a 10-coordinate geometry to two equivalent Cs(1), two equivalent K(1), one Mg(3), one Mg(4), two equivalent Mg(1), and two equivalent Mg(2) atoms. In the fifth Mg site, Mg(3) is bonded in a 10-coordinate geometry to two equivalent K(1); two equivalent Mg(2); two equivalent Mg(4); and four Mg(1,1) atoms. In the sixth Mg site, Mg(4) is bonded in a 10-coordinate geometry to two equivalent Cs(1); two equivalent Mg(2); two equivalent Mg(3); and four Mg(1,1) atoms. In the seventh Mg site, Mg(1) is bonded in a 9-coordinate geometry to one Cs(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms. In the eighth Mg site, Mg(1) is bonded in a 9-coordinate geometry to one Cs(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms. In the ninth Mg site, Mg(2) is bonded in a 10-coordinate geometry to two equivalent Cs(1), two equivalent K(1), one Mg(3), one Mg(4), two equivalent Mg(1), and two equivalent Mg(2) atoms.
CsKMg6 crystallizes in the orthorhombic Amm2 space group. Cs(1) is bonded in a 10-coordinate geometry to two equivalent K(1); two Mg(1,1); two equivalent Mg(4); and four Mg(2,2) atoms. Both Cs(1)-K(1) bond lengths are 3.34 Å. Both Cs(1)-Mg(1,1) bond lengths are 4.19 Å. Both Cs(1)-Mg(4) bond lengths are 3.93 Å. All Cs(1)-Mg(2,2) bond lengths are 3.99 Å. K(1) is bonded to two equivalent Cs(1); two equivalent Mg(3); and four Mg(2,2) atoms to form a mixture of distorted face and corner-sharing KCs2Mg6 hexagonal bipyramids. Both K(1)-Mg(3) bond lengths are 3.94 Å. All K(1)-Mg(2,2) bond lengths are 3.89 Å. There are nine inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 9-coordinate geometry to one Cs(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms. There is one shorter (3.31 Å) and one longer (3.36 Å) Mg(1)-Mg(1) bond length. Both Mg(1)-Mg(2) bond lengths are 3.11 Å. Both Mg(1)-Mg(3) bond lengths are 3.21 Å. Both Mg(1)-Mg(4) bond lengths are 3.18 Å. In the second Mg site, Mg(1) is bonded in a 9-coordinate geometry to one Cs(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms. Both Mg(1)-Mg(2) bond lengths are 3.11 Å. Both Mg(1)-Mg(3) bond lengths are 3.21 Å. Both Mg(1)-Mg(4) bond lengths are 3.18 Å. In the third Mg site, Mg(2) is bonded in a 10-coordinate geometry to two equivalent Cs(1), two equivalent K(1), one Mg(3), one Mg(4), two equivalent Mg(1), and two equivalent Mg(2) atoms. The Mg(2)-Mg(3) bond length is 3.22 Å. The Mg(2)-Mg(4) bond length is 3.10 Å. Both Mg(2)-Mg(1) bond lengths are 3.11 Å. There is one shorter (3.31 Å) and one longer (3.36 Å) Mg(2)-Mg(2) bond length. In the fourth Mg site, Mg(2) is bonded in a 10-coordinate geometry to two equivalent Cs(1), two equivalent K(1), one Mg(3), one Mg(4), two equivalent Mg(1), and two equivalent Mg(2) atoms. The Mg(2)-Mg(3) bond length is 3.22 Å. The Mg(2)-Mg(4) bond length is 3.10 Å. Both Mg(2)-Mg(1) bond lengths are 3.11 Å. In the fifth Mg site, Mg(3) is bonded in a 10-coordinate geometry to two equivalent K(1); two equivalent Mg(2); two equivalent Mg(4); and four Mg(1,1) atoms. Both Mg(3)-Mg(2) bond lengths are 3.22 Å. Both Mg(3)-Mg(4) bond lengths are 3.34 Å. In the sixth Mg site, Mg(4) is bonded in a 10-coordinate geometry to two equivalent Cs(1); two equivalent Mg(2); two equivalent Mg(3); and four Mg(1,1) atoms. Both Mg(4)-Mg(2) bond lengths are 3.10 Å. In the seventh Mg site, Mg(1) is bonded in a 9-coordinate geometry to one Cs(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms. The Mg(1)-Cs(1) bond length is 4.19 Å. There is one shorter (3.31 Å) and one longer (3.36 Å) Mg(1)-Mg(1) bond length. Both Mg(1)-Mg(3) bond lengths are 3.21 Å. Both Mg(1)-Mg(4) bond lengths are 3.18 Å. In the eighth Mg site, Mg(1) is bonded in a 9-coordinate geometry to one Cs(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms. The Mg(1)-Cs(1) bond length is 4.19 Å. Both Mg(1)-Mg(3) bond lengths are 3.21 Å. Both Mg(1)-Mg(4) bond lengths are 3.18 Å. In the ninth Mg site, Mg(2) is bonded in a 10-coordinate geometry to two equivalent Cs(1), two equivalent K(1), one Mg(3), one Mg(4), two equivalent Mg(1), and two equivalent Mg(2) atoms. Both Mg(2)-Cs(1) bond lengths are 3.99 Å. Both Mg(2)-K(1) bond lengths are 3.89 Å. There is one shorter (3.31 Å) and one longer (3.36 Å) Mg(2)-Mg(2) bond length.