data_BaNbSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.49
_cell_length_b   3.49
_cell_length_c   7.65
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BaNbSi2
_chemical_formula_sum   'Ba1 Nb1 Si2'
_cell_volume   92.9
_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
  Ba  Ba0  1  0.74  0.74  0.75  1.0
  Nb  Nb1  1  0.0  0.0  0.55  1.0
  Si  Si2  1  0.74  0.74  0.43  1.0
  Si  Si3  1  0.0  0.0  0.38  1.0

data_BaNbSi2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.93
_cell_length_b   4.93
_cell_length_c   7.65
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   BaNbSi2
_chemical_formula_sum   'Ba2 Nb2 Si4'
_cell_volume   185.8
_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
  Ba  Ba0  2  0.24  0.5  0.75  1.0
  Nb  Nb1  2  0.0  0.0  0.55  1.0
  Si  Si2  2  0.0  0.0  0.38  1.0
  Si  Si3  2  0.24  0.5  0.43  1.0

Ba Nb Si Si
Ba Nb Si Si 0 1 + + o 1 3 o o o 1 2 - - o 2 3 + + o 