data_[Be4Nb2O4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Be  1.5700  1.0500  0.5900
  Nb  1.6000  1.4500  0.8200
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [P4/mbm]
_cell_length_a [6.4678]
_cell_length_b [6.4678]
_cell_length_c [2.5900]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [127]
_chemical_formula_structural [Be2NbO2]
_chemical_formula_sum '[Be4 Nb2 O4]'
_cell_volume [108.3434]
_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
[
  Be  Be0  4  0.1167  0.3833  0.0000  1
  Nb  Nb1  2  0.0000  0.0000  0.0000  1
  O  O2  4  0.2138  0.2862  0.5000  1
]