data_KMgSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.33
_cell_length_b   8.33
_cell_length_c   8.33
_cell_angle_alpha   27.03
_cell_angle_beta   27.03
_cell_angle_gamma   27.03
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KMgSe2
_chemical_formula_sum   'K1 Mg1 Se2'
_cell_volume   105.45
_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  0.04  1.0
  Mg  Mg1  1  0.0  0.0  0.0  1.0
  Se  Se2  1  0.0  0.0  0.43  1.0
  Se  Se3  1  0.0  0.0  0.64  1.0

data_KMgSe2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.75
_cell_length_b   3.9
_cell_length_c   8.33
_cell_angle_alpha   90.0
_cell_angle_beta   105.66
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   KMgSe2
_chemical_formula_sum   'K2 Mg2 Se4'
_cell_volume   210.9
_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  0.96  1.0
  Mg  Mg1  2  0.0  0.0  0.0  1.0
  Se  Se2  2  0.0  0.0  0.36  1.0
  Se  Se3  2  0.0  0.0  0.57  1.0

K Mg Se Se
K Mg Se Se 0 1 o o o 2 3 o o o 