data_MgMn2Nb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.34
_cell_length_b   4.34
_cell_length_c   3.12
_cell_angle_alpha   91.41
_cell_angle_beta   91.41
_cell_angle_gamma   92.08
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgMn2Nb
_chemical_formula_sum   'Mg1 Mn2 Nb1'
_cell_volume   58.5
_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
  Mg  Mg0  1  0.0  0.0  0.0  1.0
  Mn  Mn1  1  0.45  0.44  0.56  1.0
  Mn  Mn2  1  0.45  0.56  0.56  1.0
  Nb  Nb3  1  0.01  0.0  0.0  1.0

data_MgMn2Nb
_symmetry_space_group_name_H-M   Pm
_cell_length_a   3.12
_cell_length_b   4.34
_cell_length_c   4.34
_cell_angle_alpha   90.0
_cell_angle_beta   91.41
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   6
_chemical_formula_structural   MgMn2Nb
_chemical_formula_sum   'Mg1 Mn2 Nb1'
_cell_volume   58.56
_cell_formula_units_Z   1
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
  Mg  Mg0  1  0.0  0.0  0.0  1.0
  Mn  Mn1  2  0.56  0.44  0.45  1.0
  Nb  Nb2  1  0.0  0.0  0.01  1.0

Mg Mn Mn Nb
Mg Mn Mn Nb 0 3 o o o 1 2 o o o 