data_MgNbSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.78
_cell_length_b   6.78
_cell_length_c   6.78
_cell_angle_alpha   156.0
_cell_angle_beta   156.0
_cell_angle_gamma   34.2
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgNbSi
_chemical_formula_sum   'Mg1 Nb1 Si1'
_cell_volume   51.56
_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  0.07  1.0
  Nb  Nb1  1  0.0  0.0  0.16  1.0
  Si  Si2  1  0.0  0.0  0.74  1.0

data_MgNbSi
_symmetry_space_group_name_H-M   Cm
_cell_length_a   3.99
_cell_length_b   3.99
_cell_length_c   6.78
_cell_angle_alpha   90.0
_cell_angle_beta   107.1
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   MgNbSi
_chemical_formula_sum   'Mg2 Nb2 Si2'
_cell_volume   103.11
_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
  Mg  Mg0  2  0.0  0.0  0.93  1.0
  Nb  Nb1  2  0.0  0.0  0.84  1.0
  Si  Si2  2  0.0  0.0  0.26  1.0

Mg Nb Si
Mg Nb Si 0 1 o o o 0 2 o o - 1 2 o o - 2 2 + o + 2 2 o + + 