data_KMg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.82
_cell_length_b   3.85
_cell_length_c   7.27
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KMg
_chemical_formula_sum   'K2 Mg2'
_cell_volume   162.97
_cell_formula_units_Z   2
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  0.46  0.92  0.89  1.0
  K  K1  1  0.37  0.92  0.38  1.0
  Mg  Mg2  1  0.37  0.0  0.48  1.0
  Mg  Mg3  1  0.46  0.0  0.8  1.0

data_KMg
_symmetry_space_group_name_H-M   P2
_cell_length_a   5.82
_cell_length_b   3.85
_cell_length_c   7.27
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   3
_chemical_formula_structural   KMg
_chemical_formula_sum   'K2 Mg2'
_cell_volume   162.97
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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  2  0.04  0.92  0.75  1.0
  Mg  Mg1  2  0.04  0.0  0.66  1.0

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