data_Na5Si4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.11
_cell_length_b   7.11
_cell_length_c   7.11
_cell_angle_alpha   95.11
_cell_angle_beta   95.11
_cell_angle_gamma   145.27
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na5Si4
_chemical_formula_sum   'Na5 Si4'
_cell_volume   195.2
_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
  Na  Na0  1  0.0  0.0  0.0  1.0
  Na  Na1  1  0.34  0.66  0.12  1.0
  Na  Na2  1  0.66  0.34  0.12  1.0
  Na  Na3  1  0.13  0.13  0.0  1.0
  Na  Na4  1  0.66  0.66  0.12  1.0
  Si  Si5  1  0.0  0.01  0.0  1.0
  Si  Si6  1  0.0  0.58  0.0  1.0
  Si  Si7  1  0.58  0.0  0.0  1.0
  Si  Si8  1  0.01  0.0  0.0  1.0

data_Na5Si4
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.24
_cell_length_b   13.57
_cell_length_c   7.11
_cell_angle_alpha   90.0
_cell_angle_beta   107.37
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Na5Si4
_chemical_formula_sum   'Na10 Si8'
_cell_volume   390.4
_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
  Na  Na0  4  0.12  0.34  0.12  1.0
  Na  Na1  2  0.0  0.0  0.0  1.0
  Na  Na2  2  0.37  0.5  -0.0  1.0
  Na  Na3  2  0.46  0.0  0.12  1.0
  Si  Si4  4  0.21  0.21  -0.0  1.0
  Si  Si5  4  0.5  0.5  -0.0  1.0

Na Na Na Na Na Si Si Si Si
Na Na Na Na Na Si Si Si Si 0 5 o o o 0 8 o o o 0 3 o o o 0 4 - - o 1 6 o o o 1 7 o + o 2 7 o o o 2 6 + o o 3 8 o o o 3 5 o o o 3 4 o o o 4 8 + + o 4 5 + + o 