The structure described by KMg6Y crystallizes in the orthorhombic Amm2 space group. K(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Y(1) atoms to form KY2Mg10 cuboctahedra that share corners with four equivalent Mg(4)K2Mg10 cuboctahedra, corners with six equivalent K(1)Y2Mg10 cuboctahedra, edges with two equivalent Mg(4)K2Mg10 cuboctahedra, edges with four equivalent Y(1)K2Mg10 cuboctahedra, faces with two equivalent K(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)K2Mg10 cuboctahedra, faces with two equivalent Y(1)K2Mg10 cuboctahedra, and faces with six equivalent Mg(2)Y2Mg10 cuboctahedra. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 11-coordinate geometry to two equivalent K(1), one Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Y(1) atoms. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with four equivalent Y(1)K2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y2Mg10 cuboctahedra, edges with two equivalent Y(1)K2Mg10 cuboctahedra, edges with four equivalent Mg(4)K2Mg10 cuboctahedra, faces with two equivalent Mg(4)K2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)K2Mg10 cuboctahedra, and faces with six equivalent K(1)Y2Mg10 cuboctahedra. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to two equivalent K(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), and two equivalent Y(1) atoms. In the fourth Mg site, Mg(4) is bonded to two equivalent K(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form distorted MgK2Mg10 cuboctahedra that share corners with four equivalent K(1)Y2Mg10 cuboctahedra, corners with six equivalent Mg(4)K2Mg10 cuboctahedra, edges with two equivalent K(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent K(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)K2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, and faces with six equivalent Y(1)K2Mg10 cuboctahedra. Y(1) is bonded to two equivalent K(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form YK2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)K2Mg10 cuboctahedra, edges with two equivalent Mg(2)Y2Mg10 cuboctahedra, edges with four equivalent K(1)Y2Mg10 cuboctahedra, faces with two equivalent K(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)K2Mg10 cuboctahedra, and faces with six equivalent Mg(4)K2Mg10 cuboctahedra. is represented by the CIF file [CIF]
data_KYMg6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.399
_cell_length_b   6.835
_cell_length_c   6.835
_cell_angle_alpha   118.689
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   221.224
_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  0.500  0.350  0.650  1.0
  Mg  Mg1  1  0.000  0.680  0.851  1.0
  Mg  Mg2  1  0.000  0.149  0.320  1.0
  Mg  Mg3  1  0.000  0.656  0.344  1.0
  Mg  Mg4  1  0.500  0.847  0.668  1.0
  Mg  Mg5  1  0.500  0.332  0.153  1.0
  Mg  Mg6  1  0.500  0.834  0.166  1.0
  Y  Y7  1  0.000  0.153  0.847  1.0
[/CIF]
.
The structure described by KMg6Y crystallizes in the orthorhombic Amm2 space group. K(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Y(1) atoms to form KY2Mg10 cuboctahedra that share corners with four equivalent Mg(4)K2Mg10 cuboctahedra, corners with six equivalent K(1)Y2Mg10 cuboctahedra, edges with two equivalent Mg(4)K2Mg10 cuboctahedra, edges with four equivalent Y(1)K2Mg10 cuboctahedra, faces with two equivalent K(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)K2Mg10 cuboctahedra, faces with two equivalent Y(1)K2Mg10 cuboctahedra, and faces with six equivalent Mg(2)Y2Mg10 cuboctahedra. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 11-coordinate geometry to two equivalent K(1), one Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Y(1) atoms. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with four equivalent Y(1)K2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y2Mg10 cuboctahedra, edges with two equivalent Y(1)K2Mg10 cuboctahedra, edges with four equivalent Mg(4)K2Mg10 cuboctahedra, faces with two equivalent Mg(4)K2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)K2Mg10 cuboctahedra, and faces with six equivalent K(1)Y2Mg10 cuboctahedra. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to two equivalent K(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), and two equivalent Y(1) atoms. In the fourth Mg site, Mg(4) is bonded to two equivalent K(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form distorted MgK2Mg10 cuboctahedra that share corners with four equivalent K(1)Y2Mg10 cuboctahedra, corners with six equivalent Mg(4)K2Mg10 cuboctahedra, edges with two equivalent K(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent K(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)K2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, and faces with six equivalent Y(1)K2Mg10 cuboctahedra. Y(1) is bonded to two equivalent K(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form YK2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)K2Mg10 cuboctahedra, edges with two equivalent Mg(2)Y2Mg10 cuboctahedra, edges with four equivalent K(1)Y2Mg10 cuboctahedra, faces with two equivalent K(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)K2Mg10 cuboctahedra, and faces with six equivalent Mg(4)K2Mg10 cuboctahedra. is represented by the CIF file [CIF]
data_KYMg6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.399
_cell_length_b   6.835
_cell_length_c   6.835
_cell_angle_alpha   118.689
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   221.224
_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  0.500  0.350  0.650  1.0
  Mg  Mg1  1  0.000  0.680  0.851  1.0
  Mg  Mg2  1  0.000  0.149  0.320  1.0
  Mg  Mg3  1  0.000  0.656  0.344  1.0
  Mg  Mg4  1  0.500  0.847  0.668  1.0
  Mg  Mg5  1  0.500  0.332  0.153  1.0
  Mg  Mg6  1  0.500  0.834  0.166  1.0
  Y  Y7  1  0.000  0.153  0.847  1.0
[/CIF]
.