data_KMg3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.42
_cell_length_b   3.42
_cell_length_c   11.47
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KMg3
_chemical_formula_sum   'K1 Mg3'
_cell_volume   116.27
_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  0.0  0.0  0.74  1.0
  Mg  Mg1  1  0.0  0.0  0.0  1.0
  Mg  Mg2  1  0.0  0.98  0.97  1.0
  Mg  Mg3  1  0.0  0.98  0.5  1.0

data_KMg3
_symmetry_space_group_name_H-M   Cm
_cell_length_a   3.42
_cell_length_b   5.93
_cell_length_c   11.47
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   KMg3
_chemical_formula_sum   'K2 Mg6'
_cell_volume   232.54
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.74  1.0
  Mg  Mg1  2  0.0  0.0  0.0  1.0
  Mg  Mg2  2  0.48  0.5  0.5  1.0
  Mg  Mg3  2  0.48  0.5  0.97  1.0

K Mg Mg Mg
K Mg Mg Mg 0 0 + + o 0 0 o + o 0 0 + o o 0 3 o - o 0 2 o - o 0 1 o o + 1 2 o - - 3 3 + + o 3 3 o + o 3 3 + o o 