CsKMg6O7 crystallizes in the tetragonal P4mm space group. Cs(1) is bonded in a 5-coordinate geometry to one O(1) and four equivalent O(5) atoms. K(1) is bonded to one O(1) and four equivalent O(4) atoms to form KO5 square pyramids that share corners with four equivalent K(1)O5 square pyramids, edges with four equivalent Mg(1)O6 octahedra, and edges with four equivalent Mg(4)O6 octahedra. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(2), one O(3), and four equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(4)O6 octahedra, and edges with four equivalent K(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 0-4°. In the second Mg site, Mg(2) is bonded to one O(2), one O(3), and four equivalent O(5) atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the third Mg site, Mg(3) is bonded in a distorted square co-planar geometry to one O(4), one O(5), and two equivalent O(2) atoms. In the fourth Mg site, Mg(4) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with four equivalent Mg(4)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with four equivalent Mg(4)O6 octahedra, and edges with two equivalent K(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 2-8°. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Cs(1), one K(1), and four equivalent Mg(4) atoms to form OCsKMg4 octahedra that share corners with four equivalent O(1)CsKMg4 octahedra, edges with four equivalent O(5)Cs2Mg4 octahedra, edges with four equivalent O(4)K2Mg4 octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles are 8°. In the second O site, O(2) is bonded to one Mg(1), one Mg(2), and four equivalent Mg(3) atoms to form OMg6 octahedra that share corners with two equivalent O(3)Mg6 octahedra, corners with four equivalent O(2)Mg6 octahedra, edges with four equivalent O(5)Cs2Mg4 octahedra, and edges with four equivalent O(4)K2Mg4 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the third O site, O(3) is bonded to one Mg(1), one Mg(2), and four equivalent Mg(4) atoms to form OMg6 octahedra that share corners with two equivalent O(2)Mg6 octahedra, corners with four equivalent O(3)Mg6 octahedra, edges with four equivalent O(5)Cs2Mg4 octahedra, edges with four equivalent O(1)CsKMg4 octahedra, and edges with four equivalent O(4)K2Mg4 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the fourth O site, O(4) is bonded to two equivalent K(1), one Mg(3), one Mg(4), and two equivalent Mg(1) atoms to form OK2Mg4 octahedra that share corners with two equivalent O(5)Cs2Mg4 octahedra, corners with four equivalent O(4)K2Mg4 octahedra, edges with two equivalent O(1)CsKMg4 octahedra, edges with two equivalent O(2)Mg6 octahedra, edges with two equivalent O(3)Mg6 octahedra, and edges with four equivalent O(4)K2Mg4 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the fifth O site, O(5) is bonded to two equivalent Cs(1), one Mg(3), one Mg(4), and two equivalent Mg(2) atoms to form distorted OCs2Mg4 octahedra that share corners with two equivalent O(4)K2Mg4 octahedra, corners with four equivalent O(5)Cs2Mg4 octahedra, edges with two equivalent O(1)CsKMg4 octahedra, edges with two equivalent O(2)Mg6 octahedra, edges with two equivalent O(3)Mg6 octahedra, and edges with four equivalent O(5)Cs2Mg4 octahedra. The corner-sharing octahedral tilt angles range from 0-28°.
CsKMg6O7 crystallizes in the tetragonal P4mm space group. Cs(1) is bonded in a 5-coordinate geometry to one O(1) and four equivalent O(5) atoms. The Cs(1)-O(1) bond length is 2.47 Å. All Cs(1)-O(5) bond lengths are 2.57 Å. K(1) is bonded to one O(1) and four equivalent O(4) atoms to form KO5 square pyramids that share corners with four equivalent K(1)O5 square pyramids, edges with four equivalent Mg(1)O6 octahedra, and edges with four equivalent Mg(4)O6 octahedra. The K(1)-O(1) bond length is 2.29 Å. All K(1)-O(4) bond lengths are 2.50 Å. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(2), one O(3), and four equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(4)O6 octahedra, and edges with four equivalent K(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 0-4°. The Mg(1)-O(2) bond length is 2.05 Å. The Mg(1)-O(3) bond length is 1.99 Å. All Mg(1)-O(4) bond lengths are 2.50 Å. In the second Mg site, Mg(2) is bonded to one O(2), one O(3), and four equivalent O(5) atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. The Mg(2)-O(2) bond length is 2.04 Å. The Mg(2)-O(3) bond length is 1.98 Å. All Mg(2)-O(5) bond lengths are 2.50 Å. In the third Mg site, Mg(3) is bonded in a distorted square co-planar geometry to one O(4), one O(5), and two equivalent O(2) atoms. The Mg(3)-O(4) bond length is 1.92 Å. The Mg(3)-O(5) bond length is 2.00 Å. Both Mg(3)-O(2) bond lengths are 2.50 Å. In the fourth Mg site, Mg(4) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with four equivalent Mg(4)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with four equivalent Mg(4)O6 octahedra, and edges with two equivalent K(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 2-8°. The Mg(4)-O(4) bond length is 2.10 Å. The Mg(4)-O(5) bond length is 2.03 Å. Both Mg(4)-O(1) bond lengths are 2.50 Å. Both Mg(4)-O(3) bond lengths are 2.50 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Cs(1), one K(1), and four equivalent Mg(4) atoms to form OCsKMg4 octahedra that share corners with four equivalent O(1)CsKMg4 octahedra, edges with four equivalent O(5)Cs2Mg4 octahedra, edges with four equivalent O(4)K2Mg4 octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles are 8°. In the second O site, O(2) is bonded to one Mg(1), one Mg(2), and four equivalent Mg(3) atoms to form OMg6 octahedra that share corners with two equivalent O(3)Mg6 octahedra, corners with four equivalent O(2)Mg6 octahedra, edges with four equivalent O(5)Cs2Mg4 octahedra, and edges with four equivalent O(4)K2Mg4 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the third O site, O(3) is bonded to one Mg(1), one Mg(2), and four equivalent Mg(4) atoms to form OMg6 octahedra that share corners with two equivalent O(2)Mg6 octahedra, corners with four equivalent O(3)Mg6 octahedra, edges with four equivalent O(5)Cs2Mg4 octahedra, edges with four equivalent O(1)CsKMg4 octahedra, and edges with four equivalent O(4)K2Mg4 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the fourth O site, O(4) is bonded to two equivalent K(1), one Mg(3), one Mg(4), and two equivalent Mg(1) atoms to form OK2Mg4 octahedra that share corners with two equivalent O(5)Cs2Mg4 octahedra, corners with four equivalent O(4)K2Mg4 octahedra, edges with two equivalent O(1)CsKMg4 octahedra, edges with two equivalent O(2)Mg6 octahedra, edges with two equivalent O(3)Mg6 octahedra, and edges with four equivalent O(4)K2Mg4 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the fifth O site, O(5) is bonded to two equivalent Cs(1), one Mg(3), one Mg(4), and two equivalent Mg(2) atoms to form distorted OCs2Mg4 octahedra that share corners with two equivalent O(4)K2Mg4 octahedra, corners with four equivalent O(5)Cs2Mg4 octahedra, edges with two equivalent O(1)CsKMg4 octahedra, edges with two equivalent O(2)Mg6 octahedra, edges with two equivalent O(3)Mg6 octahedra, and edges with four equivalent O(5)Cs2Mg4 octahedra. The corner-sharing octahedral tilt angles range from 0-28°.