data_[K4Mg2Be4O8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  K  0.8200  2.2000  1.5200
  Mg  1.3100  1.5000  0.8600
  Be  1.5700  1.0500  0.5900
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [11.8826]
_cell_length_b [3.0342]
_cell_length_c [6.1395]
_cell_angle_alpha [90.0000]
_cell_angle_beta [108.4948]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [K2MgBe2O4]
_chemical_formula_sum '[K4 Mg2 Be4 O8]'
_cell_volume [209.9241]
_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
[
  K  K0  4  0.1276  0.0000  0.5285  1.0
  Mg  Mg1  2  0.0000  0.0000  0.0000  1.0
  Be  Be2  4  0.1752  0.5000  0.9743  1.0
  O  O3  4  0.0420  0.5000  0.8081  1.0
  O  O4  4  0.2063  0.0000  0.1250  1.0
]