RbMg14CoO16 is Caswellsilverite-derived structured and crystallizes in the orthorhombic Pmmm space group. Rb(1) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(8) atoms to form RbO6 octahedra that share corners with two equivalent Rb(1)O6 octahedra; corners with two equivalent Mg(2)O6 octahedra; corners with two equivalent Co(1)O6 octahedra; edges with four equivalent Mg(3)O6 octahedra; edges with four Mg(6,6)O6 octahedra; and edges with four equivalent Mg(7)O6 octahedra. The corner-sharing octahedra are not tilted. There are eight inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1), two equivalent O(6), and two equivalent O(9) atoms to form MgO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, corners with two equivalent Co(1)O6 octahedra, edges with four equivalent Mg(4)O6 octahedra, edges with four equivalent Mg(5)O6 octahedra, and edges with four equivalent Mg(7)O6 octahedra. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to two equivalent O(2), two equivalent O(7), and two equivalent O(9) atoms to form MgO6 octahedra that share corners with two equivalent Rb(1)O6 octahedra; corners with two equivalent Mg(1)O6 octahedra; corners with two equivalent Mg(2)O6 octahedra; edges with four equivalent Mg(4)O6 octahedra; edges with four Mg(6,6)O6 octahedra; and edges with four equivalent Mg(7)O6 octahedra. The corner-sharing octahedra are not tilted. In the third Mg site, Mg(3) is bonded to one O(4), one O(5), two equivalent O(3), and two equivalent O(8) atoms to form MgO6 octahedra that share corners with two equivalent Mg(4)O6 octahedra; corners with four equivalent Mg(3)O6 octahedra; edges with two equivalent Rb(1)O6 octahedra; edges with two equivalent Mg(5)O6 octahedra; edges with two Mg(6,6)O6 octahedra; edges with two equivalent Co(1)O6 octahedra; and edges with four equivalent Mg(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the fourth Mg site, Mg(4) is bonded to one O(6), one O(7), two equivalent O(3), and two equivalent O(9) atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the fifth Mg site, Mg(5) is bonded to one O(4), one O(6), two equivalent O(1), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(6)O6 octahedra, corners with four equivalent Mg(5)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(3)O6 octahedra, edges with two equivalent Mg(4)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with four equivalent Mg(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-5°. In the sixth Mg site, Mg(6) is bonded to one O(5), one O(7), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(5)O6 octahedra; corners with four Mg(6,6)O6 octahedra; edges with two equivalent Rb(1)O6 octahedra; edges with two equivalent Mg(2)O6 octahedra; edges with two equivalent Mg(3)O6 octahedra; edges with two equivalent Mg(4)O6 octahedra; and edges with four equivalent Mg(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the seventh Mg site, Mg(6) is bonded to one O(5), one O(7), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(5)O6 octahedra; corners with four Mg(6,6)O6 octahedra; edges with two equivalent Rb(1)O6 octahedra; edges with two equivalent Mg(2)O6 octahedra; edges with two equivalent Mg(3)O6 octahedra; edges with two equivalent Mg(4)O6 octahedra; and edges with four equivalent Mg(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the eighth Mg site, Mg(7) is bonded to one O(1), one O(2), one O(8), one O(9), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with six equivalent Mg(7)O6 octahedra,  an edgeedge with one Rb(1)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra, edges with two equivalent Mg(3)O6 octahedra, edges with two equivalent Mg(4)O6 octahedra, edges with two equivalent Mg(5)O6 octahedra, and edges with two equivalent Mg(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-13°. Co(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(8) atoms to form CoO6 octahedra that share corners with two equivalent Rb(1)O6 octahedra, corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Co(1)O6 octahedra, edges with four equivalent Mg(3)O6 octahedra, edges with four equivalent Mg(5)O6 octahedra, and edges with four equivalent Mg(7)O6 octahedra. The corner-sharing octahedra are not tilted. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), two equivalent Mg(5), two equivalent Mg(7), and one Co(1) atom to form OMg5Co octahedra that share corners with two equivalent O(2)RbMg5 octahedra, corners with four equivalent O(1)Mg5Co octahedra, edges with two equivalent O(4)Mg4Co2 octahedra, edges with two equivalent O(6)Mg6 octahedra, edges with two equivalent O(9)Mg6 octahedra, edges with two equivalent O(8)RbMg4Co octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. In the second O site, O(2) is bonded to one Rb(1), one Mg(2), two equivalent Mg(6), and two equivalent Mg(7) atoms to form ORbMg5 octahedra that share corners with two equivalent O(1)Mg5Co octahedra, corners with four equivalent O(2)RbMg5 octahedra, edges with two equivalent O(7)Mg6 octahedra, edges with two equivalent O(9)Mg6 octahedra, edges with two equivalent O(5)Rb2Mg4 octahedra, edges with two equivalent O(8)RbMg4Co octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the third O site, O(3) is bonded to one Mg(3), one Mg(4), one Mg(5), one Mg(6), and two equivalent Mg(7) atoms to form OMg6 octahedra that share corners with six equivalent O(3)Mg6 octahedra,  an edgeedge with one O(4)Mg4Co2 octahedra,  an edgeedge with one O(6)Mg6 octahedra,  an edgeedge with one O(7)Mg6 octahedra,  an edgeedge with one O(5)Rb2Mg4 octahedra, edges with two equivalent O(1)Mg5Co octahedra, edges with two equivalent O(9)Mg6 octahedra, edges with two equivalent O(8)RbMg4Co octahedra, and edges with two equivalent O(2)RbMg5 octahedra. The corner-sharing octahedral tilt angles range from 1-8°. In the fourth O site, O(4) is bonded to two equivalent Mg(3), two equivalent Mg(5), and two equivalent Co(1) atoms to form OMg4Co2 octahedra that share corners with two equivalent O(4)Mg4Co2 octahedra, corners with two equivalent O(6)Mg6 octahedra, corners with two equivalent O(5)Rb2Mg4 octahedra, edges with four equivalent O(1)Mg5Co octahedra, edges with four equivalent O(3)Mg6 octahedra, and edges with four equivalent O(8)RbMg4Co octahedra. The corner-sharing octahedra are not tilted. In the fifth O site, O(5) is bonded to two equivalent Rb(1); two equivalent Mg(3); and two Mg(6,6) atoms to form ORb2Mg4 octahedra that share corners with two equivalent O(4)Mg4Co2 octahedra, corners with two equivalent O(7)Mg6 octahedra, corners with two equivalent O(5)Rb2Mg4 octahedra, edges with four equivalent O(3)Mg6 octahedra, edges with four equivalent O(8)RbMg4Co octahedra, and edges with four equivalent O(2)RbMg5 octahedra. The corner-sharing octahedra are not tilted. In the sixth O site, O(6) is bonded to two equivalent Mg(1), two equivalent Mg(4), and two equivalent Mg(5) atoms to form OMg6 octahedra that share corners with two equivalent O(4)Mg4Co2 octahedra, corners with two equivalent O(6)Mg6 octahedra, corners with two equivalent O(7)Mg6 octahedra, edges with four equivalent O(1)Mg5Co octahedra, edges with four equivalent O(3)Mg6 octahedra, and edges with four equivalent O(9)Mg6 octahedra. The corner-sharing octahedra are not tilted. In the seventh O site, O(7) is bonded to two equivalent Mg(2); two equivalent Mg(4); and two Mg(6,6) atoms to form OMg6 octahedra that share corners with two equivalent O(6)Mg6 octahedra, corners with two equivalent O(7)Mg6 octahedra, corners with two equivalent O(5)Rb2Mg4 octahedra, edges with four equivalent O(3)Mg6 octahedra, edges with four equivalent O(9)Mg6 octahedra, and edges with four equivalent O(2)RbMg5 octahedra. The corner-sharing octahedra are not tilted. In the eighth O site, O(8) is bonded to one Rb(1), two equivalent Mg(3), two equivalent Mg(7), and one Co(1) atom to form ORbMg4Co octahedra that share corners with two equivalent O(9)Mg6 octahedra, corners with four equivalent O(8)RbMg4Co octahedra, edges with two equivalent O(4)Mg4Co2 octahedra, edges with two equivalent O(1)Mg5Co octahedra, edges with two equivalent O(5)Rb2Mg4 octahedra, edges with two equivalent O(2)RbMg5 octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the ninth O site, O(9) is bonded to one Mg(1), one Mg(2), two equivalent Mg(4), and two equivalent Mg(7) atoms to form OMg6 octahedra that share corners with two equivalent O(8)RbMg4Co octahedra, corners with four equivalent O(9)Mg6 octahedra, edges with two equivalent O(1)Mg5Co octahedra, edges with two equivalent O(6)Mg6 octahedra, edges with two equivalent O(7)Mg6 octahedra, edges with two equivalent O(2)RbMg5 octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°.
RbMg14CoO16 is Caswellsilverite-derived structured and crystallizes in the orthorhombic Pmmm space group. Rb(1) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(8) atoms to form RbO6 octahedra that share corners with two equivalent Rb(1)O6 octahedra; corners with two equivalent Mg(2)O6 octahedra; corners with two equivalent Co(1)O6 octahedra; edges with four equivalent Mg(3)O6 octahedra; edges with four Mg(6,6)O6 octahedra; and edges with four equivalent Mg(7)O6 octahedra. The corner-sharing octahedra are not tilted. Both Rb(1)-O(2) bond lengths are 2.45 Å. Both Rb(1)-O(5) bond lengths are 2.17 Å. Both Rb(1)-O(8) bond lengths are 2.45 Å. There are eight inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1), two equivalent O(6), and two equivalent O(9) atoms to form MgO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, corners with two equivalent Co(1)O6 octahedra, edges with four equivalent Mg(4)O6 octahedra, edges with four equivalent Mg(5)O6 octahedra, and edges with four equivalent Mg(7)O6 octahedra. The corner-sharing octahedra are not tilted. Both Mg(1)-O(1) bond lengths are 2.12 Å. Both Mg(1)-O(6) bond lengths are 2.17 Å. Both Mg(1)-O(9) bond lengths are 2.11 Å. In the second Mg site, Mg(2) is bonded to two equivalent O(2), two equivalent O(7), and two equivalent O(9) atoms to form MgO6 octahedra that share corners with two equivalent Rb(1)O6 octahedra; corners with two equivalent Mg(1)O6 octahedra; corners with two equivalent Mg(2)O6 octahedra; edges with four equivalent Mg(4)O6 octahedra; edges with four Mg(6,6)O6 octahedra; and edges with four equivalent Mg(7)O6 octahedra. The corner-sharing octahedra are not tilted. Both Mg(2)-O(2) bond lengths are 1.94 Å. Both Mg(2)-O(7) bond lengths are 2.17 Å. Both Mg(2)-O(9) bond lengths are 2.22 Å. In the third Mg site, Mg(3) is bonded to one O(4), one O(5), two equivalent O(3), and two equivalent O(8) atoms to form MgO6 octahedra that share corners with two equivalent Mg(4)O6 octahedra; corners with four equivalent Mg(3)O6 octahedra; edges with two equivalent Rb(1)O6 octahedra; edges with two equivalent Mg(5)O6 octahedra; edges with two Mg(6,6)O6 octahedra; edges with two equivalent Co(1)O6 octahedra; and edges with four equivalent Mg(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. The Mg(3)-O(4) bond length is 2.07 Å. The Mg(3)-O(5) bond length is 2.26 Å. Both Mg(3)-O(3) bond lengths are 2.18 Å. Both Mg(3)-O(8) bond lengths are 2.18 Å. In the fourth Mg site, Mg(4) is bonded to one O(6), one O(7), two equivalent O(3), and two equivalent O(9) atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. The Mg(4)-O(6) bond length is 2.15 Å. The Mg(4)-O(7) bond length is 2.18 Å. Both Mg(4)-O(3) bond lengths are 2.22 Å. Both Mg(4)-O(9) bond lengths are 2.17 Å. In the fifth Mg site, Mg(5) is bonded to one O(4), one O(6), two equivalent O(1), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(6)O6 octahedra, corners with four equivalent Mg(5)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(3)O6 octahedra, edges with two equivalent Mg(4)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with four equivalent Mg(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-5°. The Mg(5)-O(4) bond length is 2.22 Å. The Mg(5)-O(6) bond length is 2.18 Å. Both Mg(5)-O(1) bond lengths are 2.17 Å. Both Mg(5)-O(3) bond lengths are 2.17 Å. In the sixth Mg site, Mg(6) is bonded to one O(5), one O(7), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(5)O6 octahedra; corners with four Mg(6,6)O6 octahedra; edges with two equivalent Rb(1)O6 octahedra; edges with two equivalent Mg(2)O6 octahedra; edges with two equivalent Mg(3)O6 octahedra; edges with two equivalent Mg(4)O6 octahedra; and edges with four equivalent Mg(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. The Mg(6)-O(5) bond length is 2.32 Å. The Mg(6)-O(7) bond length is 2.07 Å. Both Mg(6)-O(2) bond lengths are 2.17 Å. Both Mg(6)-O(3) bond lengths are 2.17 Å. In the seventh Mg site, Mg(6) is bonded to one O(5), one O(7), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(5)O6 octahedra; corners with four Mg(6,6)O6 octahedra; edges with two equivalent Rb(1)O6 octahedra; edges with two equivalent Mg(2)O6 octahedra; edges with two equivalent Mg(3)O6 octahedra; edges with two equivalent Mg(4)O6 octahedra; and edges with four equivalent Mg(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. The Mg(6)-O(5) bond length is 2.32 Å. The Mg(6)-O(7) bond length is 2.07 Å. Both Mg(6)-O(2) bond lengths are 2.17 Å. Both Mg(6)-O(3) bond lengths are 2.17 Å. In the eighth Mg site, Mg(7) is bonded to one O(1), one O(2), one O(8), one O(9), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with six equivalent Mg(7)O6 octahedra,  an edgeedge with one Rb(1)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mg(2)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra, edges with two equivalent Mg(3)O6 octahedra, edges with two equivalent Mg(4)O6 octahedra, edges with two equivalent Mg(5)O6 octahedra, and edges with two equivalent Mg(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-13°. The Mg(7)-O(1) bond length is 2.13 Å. The Mg(7)-O(2) bond length is 2.20 Å. The Mg(7)-O(8) bond length is 2.27 Å. The Mg(7)-O(9) bond length is 2.14 Å. Both Mg(7)-O(3) bond lengths are 2.17 Å. Co(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(8) atoms to form CoO6 octahedra that share corners with two equivalent Rb(1)O6 octahedra, corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Co(1)O6 octahedra, edges with four equivalent Mg(3)O6 octahedra, edges with four equivalent Mg(5)O6 octahedra, and edges with four equivalent Mg(7)O6 octahedra. The corner-sharing octahedra are not tilted. Both Co(1)-O(1) bond lengths are 2.28 Å. Both Co(1)-O(4) bond lengths are 2.17 Å. Both Co(1)-O(8) bond lengths are 1.88 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), two equivalent Mg(5), two equivalent Mg(7), and one Co(1) atom to form OMg5Co octahedra that share corners with two equivalent O(2)RbMg5 octahedra, corners with four equivalent O(1)Mg5Co octahedra, edges with two equivalent O(4)Mg4Co2 octahedra, edges with two equivalent O(6)Mg6 octahedra, edges with two equivalent O(9)Mg6 octahedra, edges with two equivalent O(8)RbMg4Co octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. In the second O site, O(2) is bonded to one Rb(1), one Mg(2), two equivalent Mg(6), and two equivalent Mg(7) atoms to form ORbMg5 octahedra that share corners with two equivalent O(1)Mg5Co octahedra, corners with four equivalent O(2)RbMg5 octahedra, edges with two equivalent O(7)Mg6 octahedra, edges with two equivalent O(9)Mg6 octahedra, edges with two equivalent O(5)Rb2Mg4 octahedra, edges with two equivalent O(8)RbMg4Co octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the third O site, O(3) is bonded to one Mg(3), one Mg(4), one Mg(5), one Mg(6), and two equivalent Mg(7) atoms to form OMg6 octahedra that share corners with six equivalent O(3)Mg6 octahedra,  an edgeedge with one O(4)Mg4Co2 octahedra,  an edgeedge with one O(6)Mg6 octahedra,  an edgeedge with one O(7)Mg6 octahedra,  an edgeedge with one O(5)Rb2Mg4 octahedra, edges with two equivalent O(1)Mg5Co octahedra, edges with two equivalent O(9)Mg6 octahedra, edges with two equivalent O(8)RbMg4Co octahedra, and edges with two equivalent O(2)RbMg5 octahedra. The corner-sharing octahedral tilt angles range from 1-8°. In the fourth O site, O(4) is bonded to two equivalent Mg(3), two equivalent Mg(5), and two equivalent Co(1) atoms to form OMg4Co2 octahedra that share corners with two equivalent O(4)Mg4Co2 octahedra, corners with two equivalent O(6)Mg6 octahedra, corners with two equivalent O(5)Rb2Mg4 octahedra, edges with four equivalent O(1)Mg5Co octahedra, edges with four equivalent O(3)Mg6 octahedra, and edges with four equivalent O(8)RbMg4Co octahedra. The corner-sharing octahedra are not tilted. In the fifth O site, O(5) is bonded to two equivalent Rb(1); two equivalent Mg(3); and two Mg(6,6) atoms to form ORb2Mg4 octahedra that share corners with two equivalent O(4)Mg4Co2 octahedra, corners with two equivalent O(7)Mg6 octahedra, corners with two equivalent O(5)Rb2Mg4 octahedra, edges with four equivalent O(3)Mg6 octahedra, edges with four equivalent O(8)RbMg4Co octahedra, and edges with four equivalent O(2)RbMg5 octahedra. The corner-sharing octahedra are not tilted. In the sixth O site, O(6) is bonded to two equivalent Mg(1), two equivalent Mg(4), and two equivalent Mg(5) atoms to form OMg6 octahedra that share corners with two equivalent O(4)Mg4Co2 octahedra, corners with two equivalent O(6)Mg6 octahedra, corners with two equivalent O(7)Mg6 octahedra, edges with four equivalent O(1)Mg5Co octahedra, edges with four equivalent O(3)Mg6 octahedra, and edges with four equivalent O(9)Mg6 octahedra. The corner-sharing octahedra are not tilted. In the seventh O site, O(7) is bonded to two equivalent Mg(2); two equivalent Mg(4); and two Mg(6,6) atoms to form OMg6 octahedra that share corners with two equivalent O(6)Mg6 octahedra, corners with two equivalent O(7)Mg6 octahedra, corners with two equivalent O(5)Rb2Mg4 octahedra, edges with four equivalent O(3)Mg6 octahedra, edges with four equivalent O(9)Mg6 octahedra, and edges with four equivalent O(2)RbMg5 octahedra. The corner-sharing octahedra are not tilted. In the eighth O site, O(8) is bonded to one Rb(1), two equivalent Mg(3), two equivalent Mg(7), and one Co(1) atom to form ORbMg4Co octahedra that share corners with two equivalent O(9)Mg6 octahedra, corners with four equivalent O(8)RbMg4Co octahedra, edges with two equivalent O(4)Mg4Co2 octahedra, edges with two equivalent O(1)Mg5Co octahedra, edges with two equivalent O(5)Rb2Mg4 octahedra, edges with two equivalent O(2)RbMg5 octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the ninth O site, O(9) is bonded to one Mg(1), one Mg(2), two equivalent Mg(4), and two equivalent Mg(7) atoms to form OMg6 octahedra that share corners with two equivalent O(8)RbMg4Co octahedra, corners with four equivalent O(9)Mg6 octahedra, edges with two equivalent O(1)Mg5Co octahedra, edges with two equivalent O(6)Mg6 octahedra, edges with two equivalent O(7)Mg6 octahedra, edges with two equivalent O(2)RbMg5 octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°.