The compound described by RbKMg14O15 crystallizes in the orthorhombic Pmm2 space group. Rb(1) is bonded in a 4-coordinate geometry to two equivalent O(11) and two equivalent O(9) atoms. K(1) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(10), and two equivalent O(6) atoms. There are ten inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(3), two equivalent O(10), and two equivalent O(7) atoms to form MgO5 trigonal bipyramids that share corners with two equivalent Mg(1)O5 trigonal bipyramids, corners with two equivalent Mg(10)O5 trigonal bipyramids, and edges with two equivalent Mg(8)O6 octahedra. In the second Mg site, Mg(2) is bonded to one O(1), one O(2), two equivalent O(11), and two equivalent O(8) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, edges with two equivalent Mg(5)O6 octahedra, edges with two equivalent Mg(10)O5 trigonal bipyramids, and edges with two equivalent Mg(7)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 3°. In the third Mg site, Mg(3) is bonded in a 6-coordinate geometry to one O(4), one O(5), one O(6), one O(7), and two equivalent O(10) atoms. In the fourth Mg site, Mg(4) is bonded in a 6-coordinate geometry to one O(4), one O(5), one O(8), one O(9), and two equivalent O(11) atoms. In the fifth Mg site, Mg(5) is bonded to one O(6), one O(8), two equivalent O(1), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Mg(5)O6 octahedra,  a cornercorner with one Mg(7)O5 trigonal bipyramid, and edges with two equivalent Mg(2)O6 octahedra. The corner-sharing octahedral tilt angles are 7°. In the sixth Mg site, Mg(6) is bonded in a trigonal planar geometry to one O(7) and two equivalent O(4) atoms. In the seventh Mg site, Mg(7) is bonded to one O(8), two equivalent O(2), and two equivalent O(5) atoms to form MgO5 trigonal bipyramids that share  a cornercorner with one Mg(5)O6 octahedra, corners with two equivalent Mg(8)O6 octahedra, corners with two equivalent Mg(7)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 0-21°. In the eighth Mg site, Mg(8) is bonded to one O(7), one O(9), two equivalent O(3), and two equivalent O(5) atoms to form MgO6 octahedra that share corners with two equivalent Mg(8)O6 octahedra, corners with two equivalent Mg(7)O5 trigonal bipyramids, edges with two equivalent Mg(1)O5 trigonal bipyramids, and edges with four equivalent Mg(10)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 7°. 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 Mg(1)O5 trigonal bipyramid, corners with four equivalent Mg(10)O5 trigonal bipyramids,  an edgeedge with one Mg(2)O6 octahedra, edges with two equivalent Mg(8)O6 octahedra, and edges with two equivalent Mg(7)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(5), and two equivalent Mg(9) atoms to form distorted OMg5 square pyramids that share  a cornercorner with one O(2)KMg5 octahedra, corners with two equivalent O(1)Mg5 square pyramids, corners with two equivalent O(6)K2Mg3 trigonal bipyramids, edges with two equivalent O(8)Mg6 octahedra, and edges with two equivalent O(11)RbMg5 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to one K(1), one Mg(2), two equivalent Mg(10), and two equivalent Mg(7) atoms to form OKMg5 octahedra that share corners with two equivalent O(2)KMg5 octahedra,  a cornercorner with one O(1)Mg5 square pyramid, corners with two equivalent O(6)K2Mg3 trigonal bipyramids, corners with two equivalent O(3)Mg5 trigonal bipyramids, edges with two equivalent O(8)Mg6 octahedra, and edges with two equivalent O(11)RbMg5 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(3) is bonded to one Mg(1), two equivalent Mg(10), and two equivalent Mg(8) atoms to form OMg5 trigonal bipyramids that share corners with two equivalent O(2)KMg5 octahedra, corners with two equivalent O(11)RbMg5 octahedra, corners with two equivalent O(3)Mg5 trigonal bipyramids, corners with two equivalent O(9)Rb2Mg3 trigonal bipyramids, and edges with two equivalent O(7)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 12-71°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Mg(3), one Mg(4), one Mg(5), one Mg(6), and two equivalent Mg(9) atoms. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Mg(3), one Mg(4), one Mg(7), one Mg(8), and two equivalent Mg(10) atoms. In the sixth O site, O(6) is bonded to two equivalent K(1), one Mg(5), and two equivalent Mg(3) atoms to form distorted OK2Mg3 trigonal bipyramids that share  a cornercorner with one O(8)Mg6 octahedra, corners with two equivalent O(2)KMg5 octahedra, corners with two equivalent O(7)Mg6 octahedra, corners with two equivalent O(1)Mg5 square pyramids, and corners with two equivalent O(6)K2Mg3 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 0-66°. In the seventh O site, O(7) is bonded to one Mg(6), one Mg(8), two equivalent Mg(1), and two equivalent Mg(3) atoms to form OMg6 octahedra that share corners with two equivalent O(7)Mg6 octahedra,  a cornercorner with one O(9)Rb2Mg3 trigonal bipyramid, corners with two equivalent O(6)K2Mg3 trigonal bipyramids, and edges with two equivalent O(3)Mg5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 10°. In the eighth O site, O(8) is bonded to one Mg(5), one Mg(7), two equivalent Mg(2), and two equivalent Mg(4) atoms to form OMg6 octahedra that share corners with two equivalent O(8)Mg6 octahedra,  a cornercorner with one O(6)K2Mg3 trigonal bipyramid, corners with two equivalent O(9)Rb2Mg3 trigonal bipyramids, edges with two equivalent O(2)KMg5 octahedra, edges with four equivalent O(11)RbMg5 octahedra, and edges with two equivalent O(1)Mg5 square pyramids. The corner-sharing octahedral tilt angles are 3°. In the ninth O site, O(9) is bonded to two equivalent Rb(1), one Mg(8), and two equivalent Mg(4) atoms to form distorted ORb2Mg3 trigonal bipyramids that share  a cornercorner with one O(7)Mg6 octahedra, corners with two equivalent O(8)Mg6 octahedra, corners with two equivalent O(3)Mg5 trigonal bipyramids, corners with two equivalent O(9)Rb2Mg3 trigonal bipyramids, and edges with four equivalent O(11)RbMg5 octahedra. The corner-sharing octahedral tilt angles range from 0-12°. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one K(1), one Mg(1), one Mg(9), and two equivalent Mg(3) atoms. In the eleventh O site, O(11) is bonded to one Rb(1), one Mg(10), one Mg(2), one Mg(9), and two equivalent Mg(4) atoms to form distorted ORbMg5 octahedra that share corners with four equivalent O(11)RbMg5 octahedra,  a cornercorner with one O(3)Mg5 trigonal bipyramid,  an edgeedge with one O(2)KMg5 octahedra, edges with two equivalent O(8)Mg6 octahedra,  an edgeedge with one O(1)Mg5 square pyramid, and edges with two equivalent O(9)Rb2Mg3 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 2-45°. is represented by the CIF card [CIF]
data_KRbMg14O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.265
_cell_length_b   8.589
_cell_length_c   9.614
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   352.161
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  K  K0  1  0.000  0.000  0.034  1.0
  Rb  Rb1  1  0.000  0.500  0.596  1.0
  Mg  Mg2  1  0.000  0.500  0.031  1.0
  Mg  Mg3  1  0.000  0.000  0.501  1.0
  Mg  Mg4  1  0.500  0.759  0.996  1.0
  Mg  Mg5  1  0.500  0.241  0.996  1.0
  Mg  Mg6  1  0.500  0.736  0.505  1.0
  Mg  Mg7  1  0.500  0.264  0.505  1.0
  Mg  Mg8  1  0.500  0.000  0.730  1.0
  Mg  Mg9  1  0.500  0.500  0.810  1.0
  Mg  Mg10  1  0.500  0.000  0.289  1.0
  Mg  Mg11  1  0.500  0.500  0.248  1.0
  Mg  Mg12  1  0.000  0.779  0.748  1.0
  Mg  Mg13  1  0.000  0.221  0.748  1.0
  Mg  Mg14  1  0.000  0.744  0.285  1.0
  Mg  Mg15  1  0.000  0.256  0.285  1.0
  O  O16  1  0.000  0.000  0.717  1.0
  O  O17  1  0.000  0.000  0.288  1.0
  O  O18  1  0.000  0.500  0.234  1.0
  O  O19  1  0.500  0.716  0.727  1.0
  O  O20  1  0.500  0.284  0.727  1.0
  O  O21  1  0.500  0.764  0.228  1.0
  O  O22  1  0.500  0.236  0.228  1.0
  O  O23  1  0.500  0.000  0.935  1.0
  O  O24  1  0.500  0.500  0.012  1.0
  O  O25  1  0.500  0.000  0.507  1.0
  O  O26  1  0.500  0.500  0.456  1.0
  O  O27  1  0.000  0.709  0.943  1.0
  O  O28  1  0.000  0.291  0.943  1.0
  O  O29  1  0.000  0.766  0.498  1.0
  O  O30  1  0.000  0.234  0.498  1.0
[/CIF]
.
The compound described by RbKMg14O15 crystallizes in the orthorhombic Pmm2 space group. Rb(1) is bonded in a 4-coordinate geometry to two equivalent O(11) and two equivalent O(9) atoms. K(1) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(10), and two equivalent O(6) atoms. There are ten inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(3), two equivalent O(10), and two equivalent O(7) atoms to form MgO5 trigonal bipyramids that share corners with two equivalent Mg(1)O5 trigonal bipyramids, corners with two equivalent Mg(10)O5 trigonal bipyramids, and edges with two equivalent Mg(8)O6 octahedra. In the second Mg site, Mg(2) is bonded to one O(1), one O(2), two equivalent O(11), and two equivalent O(8) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, edges with two equivalent Mg(5)O6 octahedra, edges with two equivalent Mg(10)O5 trigonal bipyramids, and edges with two equivalent Mg(7)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 3°. In the third Mg site, Mg(3) is bonded in a 6-coordinate geometry to one O(4), one O(5), one O(6), one O(7), and two equivalent O(10) atoms. In the fourth Mg site, Mg(4) is bonded in a 6-coordinate geometry to one O(4), one O(5), one O(8), one O(9), and two equivalent O(11) atoms. In the fifth Mg site, Mg(5) is bonded to one O(6), one O(8), two equivalent O(1), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Mg(5)O6 octahedra,  a cornercorner with one Mg(7)O5 trigonal bipyramid, and edges with two equivalent Mg(2)O6 octahedra. The corner-sharing octahedral tilt angles are 7°. In the sixth Mg site, Mg(6) is bonded in a trigonal planar geometry to one O(7) and two equivalent O(4) atoms. In the seventh Mg site, Mg(7) is bonded to one O(8), two equivalent O(2), and two equivalent O(5) atoms to form MgO5 trigonal bipyramids that share  a cornercorner with one Mg(5)O6 octahedra, corners with two equivalent Mg(8)O6 octahedra, corners with two equivalent Mg(7)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 0-21°. In the eighth Mg site, Mg(8) is bonded to one O(7), one O(9), two equivalent O(3), and two equivalent O(5) atoms to form MgO6 octahedra that share corners with two equivalent Mg(8)O6 octahedra, corners with two equivalent Mg(7)O5 trigonal bipyramids, edges with two equivalent Mg(1)O5 trigonal bipyramids, and edges with four equivalent Mg(10)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 7°. 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 Mg(1)O5 trigonal bipyramid, corners with four equivalent Mg(10)O5 trigonal bipyramids,  an edgeedge with one Mg(2)O6 octahedra, edges with two equivalent Mg(8)O6 octahedra, and edges with two equivalent Mg(7)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(5), and two equivalent Mg(9) atoms to form distorted OMg5 square pyramids that share  a cornercorner with one O(2)KMg5 octahedra, corners with two equivalent O(1)Mg5 square pyramids, corners with two equivalent O(6)K2Mg3 trigonal bipyramids, edges with two equivalent O(8)Mg6 octahedra, and edges with two equivalent O(11)RbMg5 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to one K(1), one Mg(2), two equivalent Mg(10), and two equivalent Mg(7) atoms to form OKMg5 octahedra that share corners with two equivalent O(2)KMg5 octahedra,  a cornercorner with one O(1)Mg5 square pyramid, corners with two equivalent O(6)K2Mg3 trigonal bipyramids, corners with two equivalent O(3)Mg5 trigonal bipyramids, edges with two equivalent O(8)Mg6 octahedra, and edges with two equivalent O(11)RbMg5 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(3) is bonded to one Mg(1), two equivalent Mg(10), and two equivalent Mg(8) atoms to form OMg5 trigonal bipyramids that share corners with two equivalent O(2)KMg5 octahedra, corners with two equivalent O(11)RbMg5 octahedra, corners with two equivalent O(3)Mg5 trigonal bipyramids, corners with two equivalent O(9)Rb2Mg3 trigonal bipyramids, and edges with two equivalent O(7)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 12-71°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Mg(3), one Mg(4), one Mg(5), one Mg(6), and two equivalent Mg(9) atoms. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Mg(3), one Mg(4), one Mg(7), one Mg(8), and two equivalent Mg(10) atoms. In the sixth O site, O(6) is bonded to two equivalent K(1), one Mg(5), and two equivalent Mg(3) atoms to form distorted OK2Mg3 trigonal bipyramids that share  a cornercorner with one O(8)Mg6 octahedra, corners with two equivalent O(2)KMg5 octahedra, corners with two equivalent O(7)Mg6 octahedra, corners with two equivalent O(1)Mg5 square pyramids, and corners with two equivalent O(6)K2Mg3 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 0-66°. In the seventh O site, O(7) is bonded to one Mg(6), one Mg(8), two equivalent Mg(1), and two equivalent Mg(3) atoms to form OMg6 octahedra that share corners with two equivalent O(7)Mg6 octahedra,  a cornercorner with one O(9)Rb2Mg3 trigonal bipyramid, corners with two equivalent O(6)K2Mg3 trigonal bipyramids, and edges with two equivalent O(3)Mg5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 10°. In the eighth O site, O(8) is bonded to one Mg(5), one Mg(7), two equivalent Mg(2), and two equivalent Mg(4) atoms to form OMg6 octahedra that share corners with two equivalent O(8)Mg6 octahedra,  a cornercorner with one O(6)K2Mg3 trigonal bipyramid, corners with two equivalent O(9)Rb2Mg3 trigonal bipyramids, edges with two equivalent O(2)KMg5 octahedra, edges with four equivalent O(11)RbMg5 octahedra, and edges with two equivalent O(1)Mg5 square pyramids. The corner-sharing octahedral tilt angles are 3°. In the ninth O site, O(9) is bonded to two equivalent Rb(1), one Mg(8), and two equivalent Mg(4) atoms to form distorted ORb2Mg3 trigonal bipyramids that share  a cornercorner with one O(7)Mg6 octahedra, corners with two equivalent O(8)Mg6 octahedra, corners with two equivalent O(3)Mg5 trigonal bipyramids, corners with two equivalent O(9)Rb2Mg3 trigonal bipyramids, and edges with four equivalent O(11)RbMg5 octahedra. The corner-sharing octahedral tilt angles range from 0-12°. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one K(1), one Mg(1), one Mg(9), and two equivalent Mg(3) atoms. In the eleventh O site, O(11) is bonded to one Rb(1), one Mg(10), one Mg(2), one Mg(9), and two equivalent Mg(4) atoms to form distorted ORbMg5 octahedra that share corners with four equivalent O(11)RbMg5 octahedra,  a cornercorner with one O(3)Mg5 trigonal bipyramid,  an edgeedge with one O(2)KMg5 octahedra, edges with two equivalent O(8)Mg6 octahedra,  an edgeedge with one O(1)Mg5 square pyramid, and edges with two equivalent O(9)Rb2Mg3 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 2-45°. is represented by the CIF card [CIF]
data_KRbMg14O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.265
_cell_length_b   8.589
_cell_length_c   9.614
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   352.161
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  K  K0  1  0.000  0.000  0.034  1.0
  Rb  Rb1  1  0.000  0.500  0.596  1.0
  Mg  Mg2  1  0.000  0.500  0.031  1.0
  Mg  Mg3  1  0.000  0.000  0.501  1.0
  Mg  Mg4  1  0.500  0.759  0.996  1.0
  Mg  Mg5  1  0.500  0.241  0.996  1.0
  Mg  Mg6  1  0.500  0.736  0.505  1.0
  Mg  Mg7  1  0.500  0.264  0.505  1.0
  Mg  Mg8  1  0.500  0.000  0.730  1.0
  Mg  Mg9  1  0.500  0.500  0.810  1.0
  Mg  Mg10  1  0.500  0.000  0.289  1.0
  Mg  Mg11  1  0.500  0.500  0.248  1.0
  Mg  Mg12  1  0.000  0.779  0.748  1.0
  Mg  Mg13  1  0.000  0.221  0.748  1.0
  Mg  Mg14  1  0.000  0.744  0.285  1.0
  Mg  Mg15  1  0.000  0.256  0.285  1.0
  O  O16  1  0.000  0.000  0.717  1.0
  O  O17  1  0.000  0.000  0.288  1.0
  O  O18  1  0.000  0.500  0.234  1.0
  O  O19  1  0.500  0.716  0.727  1.0
  O  O20  1  0.500  0.284  0.727  1.0
  O  O21  1  0.500  0.764  0.228  1.0
  O  O22  1  0.500  0.236  0.228  1.0
  O  O23  1  0.500  0.000  0.935  1.0
  O  O24  1  0.500  0.500  0.012  1.0
  O  O25  1  0.500  0.000  0.507  1.0
  O  O26  1  0.500  0.500  0.456  1.0
  O  O27  1  0.000  0.709  0.943  1.0
  O  O28  1  0.000  0.291  0.943  1.0
  O  O29  1  0.000  0.766  0.498  1.0
  O  O30  1  0.000  0.234  0.498  1.0
[/CIF]
.