data_MgSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.13
_cell_length_b   8.13
_cell_length_c   2.79
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgSi2
_chemical_formula_sum   'Mg3 Si6'
_cell_volume   159.86
_cell_formula_units_Z   3
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  0.69  0.4  1.0
  Mg  Mg1  1  0.06  0.35  0.4  1.0
  Mg  Mg2  1  0.0  0.0  0.0  1.0
  Si  Si3  1  0.46  0.0  0.4  1.0
  Si  Si4  1  0.77  0.13  0.4  1.0
  Si  Si5  1  0.84  0.91  0.4  1.0
  Si  Si6  1  0.73  0.0  0.0  1.0
  Si  Si7  1  0.64  0.09  0.0  1.0
  Si  Si8  1  0.7  0.95  0.0  1.0

data_MgSi2
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.79
_cell_length_b   8.13
_cell_length_c   8.13
_cell_angle_alpha   120.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgSi2
_chemical_formula_sum   'Mg3 Si6'
_cell_volume   159.86
_cell_formula_units_Z   3
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
  Mg  Mg1  1  0.4  0.0  0.69  1.0
  Mg  Mg2  1  0.4  0.06  0.35  1.0
  Si  Si3  1  0.0  0.73  0.0  1.0
  Si  Si4  1  0.0  0.64  0.09  1.0
  Si  Si5  1  0.0  0.7  0.95  1.0
  Si  Si6  1  0.4  0.46  0.0  1.0
  Si  Si7  1  0.4  0.77  0.13  1.0
  Si  Si8  1  0.4  0.84  0.91  1.0

Mg Mg Mg Si Si Si Si Si Si