data_[Be4Si4N8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Be  1.5700  1.0500  0.5900
  Si  1.9000  1.1000  0.5400
  N  3.0400  0.6500  0.6300
]
_symmetry_space_group_name_H-M [Pna2_1]
_cell_length_a [4.9992]
_cell_length_b [5.7729]
_cell_length_c [4.7003]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [33]
_chemical_formula_structural [BeSiN2]
_chemical_formula_sum '[Be4 Si4 N8]'
_cell_volume [135.6494]
_cell_formula_units_Z [4]
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  0.0832  0.6252  0.9998  1.0
  Si  Si1  4  0.0852  0.1251  0.9993  1.0
  N  N2  4  0.0795  0.1228  0.3744  1.0
  N  N3  4  0.0842  0.6274  0.3785  1.0
]