RbLiMg14O15 crystallizes in the orthorhombic Pmm2 space group. Rb(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(10), and two equivalent O(7) atoms. Li(1) is bonded to one O(2), two equivalent O(10), and two equivalent O(6) atoms to form LiO5 trigonal bipyramids that share  a cornercorner with one Mg(1)O5 trigonal bipyramid, corners with two equivalent Li(1)O5 trigonal bipyramids, corners with two equivalent Mg(10)O5 trigonal bipyramids, edges with two equivalent Mg(7)O6 octahedra, and edges with four equivalent Mg(3)O5 trigonal bipyramids. There are ten inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(2), two equivalent O(11), and two equivalent O(8) atoms to form MgO5 trigonal bipyramids that share corners with two equivalent Mg(2)O6 octahedra,  a cornercorner with one Li(1)O5 trigonal bipyramid, corners with two equivalent Mg(1)O5 trigonal bipyramids, edges with two equivalent Mg(7)O6 octahedra, edges with two equivalent Mg(10)O5 trigonal bipyramids, and edges with four equivalent Mg(4)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 8°. In the second Mg site, Mg(2) is bonded to one O(1), one O(3), two equivalent O(11), and two equivalent O(9) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, edges with two equivalent Mg(6)O6 octahedra, edges with two equivalent Mg(10)O5 trigonal bipyramids, edges with two equivalent Mg(8)O5 trigonal bipyramids, and edges with four equivalent Mg(4)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 1°. In the third Mg site, Mg(3) is bonded to one O(5), one O(6), one O(7), and two equivalent O(10) atoms to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Mg(6)O6 octahedra,  a cornercorner with one Mg(8)O5 trigonal bipyramid, corners with two equivalent Mg(10)O5 trigonal bipyramids, corners with four equivalent Mg(3)O5 trigonal bipyramids,  an edgeedge with one Mg(7)O6 octahedra, and edges with two equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 71°. In the fourth Mg site, Mg(4) is bonded to one O(4), one O(8), one O(9), and two equivalent O(11) atoms to form MgO5 trigonal bipyramids that share  a cornercorner with one Mg(7)O6 octahedra,  a cornercorner with one Mg(8)O5 trigonal bipyramid, corners with two equivalent Mg(10)O5 trigonal bipyramids, corners with four equivalent Mg(4)O5 trigonal bipyramids,  an edgeedge with one Mg(6)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 70°. In the fifth Mg site, Mg(5) is bonded in a trigonal planar geometry to one O(6) and two equivalent O(4) atoms. In the sixth Mg site, Mg(6) is bonded to one O(7), one O(9), two equivalent O(1), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Mg(6)O6 octahedra,  a cornercorner with one Mg(8)O5 trigonal bipyramid, corners with two equivalent Mg(3)O5 trigonal bipyramids, edges with two equivalent Mg(2)O6 octahedra, and edges with two equivalent Mg(4)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 15°. In the seventh Mg site, Mg(7) is bonded to one O(6), one O(8), two equivalent O(2), and two equivalent O(5) atoms to form MgO6 octahedra that share corners with two equivalent Mg(7)O6 octahedra, corners with two equivalent Mg(4)O5 trigonal bipyramids, corners with two equivalent Mg(8)O5 trigonal bipyramids, edges with two equivalent Li(1)O5 trigonal bipyramids, edges with two equivalent Mg(1)O5 trigonal bipyramids, edges with two equivalent Mg(3)O5 trigonal bipyramids, and edges with four equivalent Mg(10)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 16°. In the eighth Mg site, Mg(8) is bonded to one O(9), two equivalent O(3), and two equivalent O(5) atoms to form MgO5 trigonal bipyramids that share  a cornercorner with one Mg(6)O6 octahedra, corners with two equivalent Mg(7)O6 octahedra, corners with two equivalent Mg(3)O5 trigonal bipyramids, corners with two equivalent Mg(4)O5 trigonal bipyramids, corners with two equivalent Mg(8)O5 trigonal bipyramids, edges with two equivalent Mg(2)O6 octahedra, and edges with four equivalent Mg(10)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 0-24°. In the ninth Mg site, Mg(9) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(11), and two equivalent O(4) atoms. In the tenth Mg site, Mg(10) is bonded to one O(11), one O(2), one O(3), and two equivalent O(5) atoms to form MgO5 trigonal bipyramids that share  a cornercorner with one Li(1)O5 trigonal bipyramid, corners with two equivalent Mg(3)O5 trigonal bipyramids, corners with two equivalent Mg(4)O5 trigonal bipyramids, corners with four equivalent Mg(10)O5 trigonal bipyramids,  an edgeedge with one Mg(2)O6 octahedra, edges with two equivalent Mg(7)O6 octahedra,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and edges with two equivalent Mg(8)O5 trigonal bipyramids. There are eleven inequivalent O sites. In the first O site, O(1) is bonded to one Mg(2), two equivalent Mg(6), and two equivalent Mg(9) atoms to form OMg5 trigonal bipyramids that share  a cornercorner with one O(3)RbMg5 octahedra, corners with two equivalent O(1)Mg5 trigonal bipyramids, edges with two equivalent O(11)Mg6 octahedra, and edges with two equivalent O(9)Mg6 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to one Li(1), one Mg(1), two equivalent Mg(10), and two equivalent Mg(7) atoms to form OLiMg5 octahedra that share corners with two equivalent O(2)LiMg5 octahedra, corners with two equivalent O(3)RbMg5 octahedra, edges with two equivalent O(6)Li2Mg4 octahedra, edges with two equivalent O(11)Mg6 octahedra, edges with two equivalent O(8)Mg5 trigonal bipyramids, and edges with four equivalent O(5)Mg5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 1-16°. In the third O site, O(3) is bonded to one Rb(1), one Mg(2), two equivalent Mg(10), and two equivalent Mg(8) atoms to form ORbMg5 octahedra that share corners with two equivalent O(2)LiMg5 octahedra, corners with two equivalent O(3)RbMg5 octahedra,  a cornercorner with one O(1)Mg5 trigonal bipyramid, edges with two equivalent O(11)Mg6 octahedra, edges with two equivalent O(9)Mg6 octahedra, and edges with four equivalent O(5)Mg5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 1-4°. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Mg(4), one Mg(5), one Mg(6), and two equivalent Mg(9) atoms. In the fifth O site, O(5) is bonded to one Mg(3), one Mg(7), one Mg(8), and two equivalent Mg(10) atoms to form distorted OMg5 trigonal bipyramids that share  a cornercorner with one O(9)Mg6 octahedra, corners with two equivalent O(11)Mg6 octahedra,  a cornercorner with one O(8)Mg5 trigonal bipyramid, corners with four equivalent O(5)Mg5 trigonal bipyramids,  an edgeedge with one O(6)Li2Mg4 octahedra, edges with two equivalent O(2)LiMg5 octahedra, and edges with two equivalent O(3)RbMg5 octahedra. The corner-sharing octahedral tilt angles range from 66-74°. In the sixth O site, O(6) is bonded to two equivalent Li(1), one Mg(5), one Mg(7), and two equivalent Mg(3) atoms to form OLi2Mg4 octahedra that share corners with two equivalent O(6)Li2Mg4 octahedra,  a cornercorner with one O(8)Mg5 trigonal bipyramid, edges with two equivalent O(2)LiMg5 octahedra, and edges with two equivalent O(5)Mg5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 3°. In the seventh O site, O(7) is bonded in a 5-coordinate geometry to two equivalent Rb(1), one Mg(6), and two equivalent Mg(3) atoms. In the eighth O site, O(8) is bonded to one Mg(7), two equivalent Mg(1), and two equivalent Mg(4) atoms to form OMg5 trigonal bipyramids that share  a cornercorner with one O(6)Li2Mg4 octahedra, corners with two equivalent O(9)Mg6 octahedra, corners with two equivalent O(5)Mg5 trigonal bipyramids, corners with two equivalent O(8)Mg5 trigonal bipyramids, edges with two equivalent O(2)LiMg5 octahedra, and edges with four equivalent O(11)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-24°. In the ninth O site, O(9) is bonded to one Mg(6), one Mg(8), two equivalent Mg(2), and two equivalent Mg(4) atoms to form OMg6 octahedra that share corners with two equivalent O(9)Mg6 octahedra, corners with two equivalent O(5)Mg5 trigonal bipyramids, corners with two equivalent O(8)Mg5 trigonal bipyramids, edges with two equivalent O(3)RbMg5 octahedra, edges with four equivalent O(11)Mg6 octahedra, and edges with two equivalent O(1)Mg5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 1°. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Rb(1), one Li(1), one Mg(9), and two equivalent Mg(3) atoms. In the eleventh O site, O(11) is bonded to one Mg(1), one Mg(10), one Mg(2), one Mg(9), and two equivalent Mg(4) atoms to form distorted OMg6 octahedra that share corners with four equivalent O(11)Mg6 octahedra, corners with two equivalent O(5)Mg5 trigonal bipyramids,  an edgeedge with one O(2)LiMg5 octahedra,  an edgeedge with one O(3)RbMg5 octahedra, edges with two equivalent O(9)Mg6 octahedra,  an edgeedge with one O(1)Mg5 trigonal bipyramid, and edges with two equivalent O(8)Mg5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 7-23°.
RbLiMg14O15 crystallizes in the orthorhombic Pmm2 space group. Rb(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(10), and two equivalent O(7) atoms. The Rb(1)-O(3) bond length is 2.60 Å. Both Rb(1)-O(10) bond lengths are 2.70 Å. Both Rb(1)-O(7) bond lengths are 2.44 Å. Li(1) is bonded to one O(2), two equivalent O(10), and two equivalent O(6) atoms to form LiO5 trigonal bipyramids that share  a cornercorner with one Mg(1)O5 trigonal bipyramid, corners with two equivalent Li(1)O5 trigonal bipyramids, corners with two equivalent Mg(10)O5 trigonal bipyramids, edges with two equivalent Mg(7)O6 octahedra, and edges with four equivalent Mg(3)O5 trigonal bipyramids. The Li(1)-O(2) bond length is 2.30 Å. Both Li(1)-O(10) bond lengths are 1.93 Å. Both Li(1)-O(6) bond lengths are 2.07 Å. There are ten inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(2), two equivalent O(11), and two equivalent O(8) atoms to form MgO5 trigonal bipyramids that share corners with two equivalent Mg(2)O6 octahedra,  a cornercorner with one Li(1)O5 trigonal bipyramid, corners with two equivalent Mg(1)O5 trigonal bipyramids, edges with two equivalent Mg(7)O6 octahedra, edges with two equivalent Mg(10)O5 trigonal bipyramids, and edges with four equivalent Mg(4)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 8°. The Mg(1)-O(2) bond length is 2.05 Å. Both Mg(1)-O(11) bond lengths are 2.02 Å. Both Mg(1)-O(8) bond lengths are 2.07 Å. In the second Mg site, Mg(2) is bonded to one O(1), one O(3), two equivalent O(11), and two equivalent O(9) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, edges with two equivalent Mg(6)O6 octahedra, edges with two equivalent Mg(10)O5 trigonal bipyramids, edges with two equivalent Mg(8)O5 trigonal bipyramids, and edges with four equivalent Mg(4)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 1°. The Mg(2)-O(1) bond length is 2.01 Å. The Mg(2)-O(3) bond length is 2.01 Å. Both Mg(2)-O(11) bond lengths are 2.17 Å. Both Mg(2)-O(9) bond lengths are 2.07 Å. In the third Mg site, Mg(3) is bonded to one O(5), one O(6), one O(7), and two equivalent O(10) atoms to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Mg(6)O6 octahedra,  a cornercorner with one Mg(8)O5 trigonal bipyramid, corners with two equivalent Mg(10)O5 trigonal bipyramids, corners with four equivalent Mg(3)O5 trigonal bipyramids,  an edgeedge with one Mg(7)O6 octahedra, and edges with two equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 71°. The Mg(3)-O(5) bond length is 2.29 Å. The Mg(3)-O(6) bond length is 2.10 Å. The Mg(3)-O(7) bond length is 2.18 Å. Both Mg(3)-O(10) bond lengths are 2.18 Å. In the fourth Mg site, Mg(4) is bonded to one O(4), one O(8), one O(9), and two equivalent O(11) atoms to form MgO5 trigonal bipyramids that share  a cornercorner with one Mg(7)O6 octahedra,  a cornercorner with one Mg(8)O5 trigonal bipyramid, corners with two equivalent Mg(10)O5 trigonal bipyramids, corners with four equivalent Mg(4)O5 trigonal bipyramids,  an edgeedge with one Mg(6)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 70°. The Mg(4)-O(4) bond length is 2.03 Å. The Mg(4)-O(8) bond length is 2.03 Å. The Mg(4)-O(9) bond length is 2.25 Å. Both Mg(4)-O(11) bond lengths are 2.09 Å. In the fifth Mg site, Mg(5) is bonded in a trigonal planar geometry to one O(6) and two equivalent O(4) atoms. The Mg(5)-O(6) bond length is 1.98 Å. Both Mg(5)-O(4) bond lengths are 2.03 Å. In the sixth Mg site, Mg(6) is bonded to one O(7), one O(9), two equivalent O(1), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Mg(6)O6 octahedra,  a cornercorner with one Mg(8)O5 trigonal bipyramid, corners with two equivalent Mg(3)O5 trigonal bipyramids, edges with two equivalent Mg(2)O6 octahedra, and edges with two equivalent Mg(4)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 15°. The Mg(6)-O(7) bond length is 1.94 Å. The Mg(6)-O(9) bond length is 2.26 Å. Both Mg(6)-O(1) bond lengths are 2.09 Å. Both Mg(6)-O(4) bond lengths are 2.39 Å. In the seventh Mg site, Mg(7) is bonded to one O(6), one O(8), two equivalent O(2), and two equivalent O(5) atoms to form MgO6 octahedra that share corners with two equivalent Mg(7)O6 octahedra, corners with two equivalent Mg(4)O5 trigonal bipyramids, corners with two equivalent Mg(8)O5 trigonal bipyramids, edges with two equivalent Li(1)O5 trigonal bipyramids, edges with two equivalent Mg(1)O5 trigonal bipyramids, edges with two equivalent Mg(3)O5 trigonal bipyramids, and edges with four equivalent Mg(10)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 16°. The Mg(7)-O(6) bond length is 2.07 Å. The Mg(7)-O(8) bond length is 2.34 Å. Both Mg(7)-O(2) bond lengths are 2.09 Å. Both Mg(7)-O(5) bond lengths are 2.24 Å. In the eighth Mg site, Mg(8) is bonded to one O(9), two equivalent O(3), and two equivalent O(5) atoms to form MgO5 trigonal bipyramids that share  a cornercorner with one Mg(6)O6 octahedra, corners with two equivalent Mg(7)O6 octahedra, corners with two equivalent Mg(3)O5 trigonal bipyramids, corners with two equivalent Mg(4)O5 trigonal bipyramids, corners with two equivalent Mg(8)O5 trigonal bipyramids, edges with two equivalent Mg(2)O6 octahedra, and edges with four equivalent Mg(10)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 0-24°. The Mg(8)-O(9) bond length is 2.11 Å. Both Mg(8)-O(3) bond lengths are 2.07 Å. Both Mg(8)-O(5) bond lengths are 2.08 Å. In the ninth Mg site, Mg(9) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(11), and two equivalent O(4) atoms. The Mg(9)-O(1) bond length is 1.97 Å. The Mg(9)-O(10) bond length is 1.93 Å. The Mg(9)-O(11) bond length is 2.63 Å. Both Mg(9)-O(4) bond lengths are 2.14 Å. In the tenth Mg site, Mg(10) is bonded to one O(11), one O(2), one O(3), and two equivalent O(5) atoms to form MgO5 trigonal bipyramids that share  a cornercorner with one Li(1)O5 trigonal bipyramid, corners with two equivalent Mg(3)O5 trigonal bipyramids, corners with two equivalent Mg(4)O5 trigonal bipyramids, corners with four equivalent Mg(10)O5 trigonal bipyramids,  an edgeedge with one Mg(2)O6 octahedra, edges with two equivalent Mg(7)O6 octahedra,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and edges with two equivalent Mg(8)O5 trigonal bipyramids. The Mg(10)-O(11) bond length is 2.19 Å. The Mg(10)-O(2) bond length is 2.11 Å. The Mg(10)-O(3) bond length is 2.08 Å. Both Mg(10)-O(5) bond lengths are 2.16 Å. There are eleven inequivalent O sites. In the first O site, O(1) is bonded to one Mg(2), two equivalent Mg(6), and two equivalent Mg(9) atoms to form OMg5 trigonal bipyramids that share  a cornercorner with one O(3)RbMg5 octahedra, corners with two equivalent O(1)Mg5 trigonal bipyramids, edges with two equivalent O(11)Mg6 octahedra, and edges with two equivalent O(9)Mg6 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to one Li(1), one Mg(1), two equivalent Mg(10), and two equivalent Mg(7) atoms to form OLiMg5 octahedra that share corners with two equivalent O(2)LiMg5 octahedra, corners with two equivalent O(3)RbMg5 octahedra, edges with two equivalent O(6)Li2Mg4 octahedra, edges with two equivalent O(11)Mg6 octahedra, edges with two equivalent O(8)Mg5 trigonal bipyramids, and edges with four equivalent O(5)Mg5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 1-16°. In the third O site, O(3) is bonded to one Rb(1), one Mg(2), two equivalent Mg(10), and two equivalent Mg(8) atoms to form ORbMg5 octahedra that share corners with two equivalent O(2)LiMg5 octahedra, corners with two equivalent O(3)RbMg5 octahedra,  a cornercorner with one O(1)Mg5 trigonal bipyramid, edges with two equivalent O(11)Mg6 octahedra, edges with two equivalent O(9)Mg6 octahedra, and edges with four equivalent O(5)Mg5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 1-4°. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Mg(4), one Mg(5), one Mg(6), and two equivalent Mg(9) atoms. In the fifth O site, O(5) is bonded to one Mg(3), one Mg(7), one Mg(8), and two equivalent Mg(10) atoms to form distorted OMg5 trigonal bipyramids that share  a cornercorner with one O(9)Mg6 octahedra, corners with two equivalent O(11)Mg6 octahedra,  a cornercorner with one O(8)Mg5 trigonal bipyramid, corners with four equivalent O(5)Mg5 trigonal bipyramids,  an edgeedge with one O(6)Li2Mg4 octahedra, edges with two equivalent O(2)LiMg5 octahedra, and edges with two equivalent O(3)RbMg5 octahedra. The corner-sharing octahedral tilt angles range from 66-74°. In the sixth O site, O(6) is bonded to two equivalent Li(1), one Mg(5), one Mg(7), and two equivalent Mg(3) atoms to form OLi2Mg4 octahedra that share corners with two equivalent O(6)Li2Mg4 octahedra,  a cornercorner with one O(8)Mg5 trigonal bipyramid, edges with two equivalent O(2)LiMg5 octahedra, and edges with two equivalent O(5)Mg5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 3°. In the seventh O site, O(7) is bonded in a 5-coordinate geometry to two equivalent Rb(1), one Mg(6), and two equivalent Mg(3) atoms. In the eighth O site, O(8) is bonded to one Mg(7), two equivalent Mg(1), and two equivalent Mg(4) atoms to form OMg5 trigonal bipyramids that share  a cornercorner with one O(6)Li2Mg4 octahedra, corners with two equivalent O(9)Mg6 octahedra, corners with two equivalent O(5)Mg5 trigonal bipyramids, corners with two equivalent O(8)Mg5 trigonal bipyramids, edges with two equivalent O(2)LiMg5 octahedra, and edges with four equivalent O(11)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-24°. In the ninth O site, O(9) is bonded to one Mg(6), one Mg(8), two equivalent Mg(2), and two equivalent Mg(4) atoms to form OMg6 octahedra that share corners with two equivalent O(9)Mg6 octahedra, corners with two equivalent O(5)Mg5 trigonal bipyramids, corners with two equivalent O(8)Mg5 trigonal bipyramids, edges with two equivalent O(3)RbMg5 octahedra, edges with four equivalent O(11)Mg6 octahedra, and edges with two equivalent O(1)Mg5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 1°. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Rb(1), one Li(1), one Mg(9), and two equivalent Mg(3) atoms. In the eleventh O site, O(11) is bonded to one Mg(1), one Mg(10), one Mg(2), one Mg(9), and two equivalent Mg(4) atoms to form distorted OMg6 octahedra that share corners with four equivalent O(11)Mg6 octahedra, corners with two equivalent O(5)Mg5 trigonal bipyramids,  an edgeedge with one O(2)LiMg5 octahedra,  an edgeedge with one O(3)RbMg5 octahedra, edges with two equivalent O(9)Mg6 octahedra,  an edgeedge with one O(1)Mg5 trigonal bipyramid, and edges with two equivalent O(8)Mg5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 7-23°.