data_[Na2Mg4Be4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Mg  1.3100  1.5000  0.8600
  Be  1.5700  1.0500  0.5900
]
_symmetry_space_group_name_H-M [I4/mmm]
_cell_length_a [4.3108]
_cell_length_b [4.3108]
_cell_length_c [10.7195]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [139]
_chemical_formula_structural [Na(MgBe)2]
_chemical_formula_sum '[Na2 Mg4 Be4]'
_cell_volume [199.1993]
_cell_formula_units_Z [2]
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  2  0.0000  0.0000  0.0000  1
  Mg  Mg1  4  0.0000  0.5000  0.2500  1
  Be  Be2  4  0.0000  0.0000  0.4021  1
]