data_Na2VSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.74
_cell_length_b   2.74
_cell_length_c   10.17
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2VSi
_chemical_formula_sum   'Na2 V1 Si1'
_cell_volume   76.53
_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  0.88  1.0
  Na  Na1  1  0.37  0.37  0.03  1.0
  V  V3  1  0.37  0.37  0.14  1.0
  Si  Si2  1  0.0  0.0  0.38  1.0

data_Na2VSi
_symmetry_space_group_name_H-M   Cm
_cell_length_a   3.88
_cell_length_b   3.88
_cell_length_c   10.17
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Na2VSi
_chemical_formula_sum   'Na4 V2 Si2'
_cell_volume   153.05
_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  2  0.0  0.0  0.88  1.0
  Na  Na1  2  0.37  0.0  0.03  1.0
  V  V2  2  0.37  0.0  0.14  1.0
  Si  Si3  2  0.0  0.0  0.38  1.0

Na Na V Si
Na Na V Si 0 1 - - + 0 1 - o + 0 1 o - + 0 1 o o + 0 0 + o o 0 0 o + o 1 2 o o o 2 3 + o o 2 3 o + o 2 3 o o o 3 3 + o o 3 3 o + o 