data_MgSi2Br
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.85
_cell_length_b   5.63
_cell_length_c   4.06
_cell_angle_alpha   90.0
_cell_angle_beta   101.01
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgSi2Br
_chemical_formula_sum   'Mg1 Si2 Br1'
_cell_volume   86.26
_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  Mg1  1  0.0  0.0  0.0  1.0
  Si  Si2  1  0.13  0.81  0.26  1.0
  Si  Si3  1  0.94  0.81  0.72  1.0
  Br  Br0  1  0.54  0.0  0.99  1.0

data_MgSi2Br
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.85
_cell_length_b   4.06
_cell_length_c   5.63
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   101.01
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgSi2Br
_chemical_formula_sum   'Mg1 Si2 Br1'
_cell_volume   86.26
_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
  Si  Si1  1  0.06  0.28  0.19  1.0
  Si  Si2  1  0.87  0.74  0.19  1.0
  Br  Br3  1  0.46  0.01  0.0  1.0

Mg Si Si Br
Mg Si Si Br 0 2 - - - 0 3 - o - 0 3 o o - 0 1 o - o 