data_KMg2Nb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.14
_cell_length_b   6.14
_cell_length_c   6.14
_cell_angle_alpha   142.28
_cell_angle_beta   126.22
_cell_angle_gamma   67.55
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KMg2Nb
_chemical_formula_sum   'K1 Mg2 Nb1'
_cell_volume   112.6
_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  0.0  1.0
  Mg  Mg1  1  0.0  0.78  0.28  1.0
  Mg  Mg2  1  0.99  0.0  0.83  1.0
  Nb  Nb3  1  0.0  0.0  0.1  1.0

data_KMg2Nb
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.97
_cell_length_b   5.55
_cell_length_c   6.14
_cell_angle_alpha   116.89
_cell_angle_beta   108.86
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KMg2Nb
_chemical_formula_sum   'K1 Mg2 Nb1'
_cell_volume   112.6
_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  0.0  1.0
  Mg  Mg1  1  0.16  0.17  0.16  1.0
  Mg  Mg2  1  0.72  0.5  0.5  1.0
  Nb  Nb3  1  0.9  0.9  0.9  1.0

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