data_MgBeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.46
_cell_length_b   5.46
_cell_length_c   5.46
_cell_angle_alpha   143.04
_cell_angle_beta   99.49
_cell_angle_gamma   92.07
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgBeSe2
_chemical_formula_sum   'Mg1 Be1 Se2'
_cell_volume   92.47
_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
  Mg  Mg1  1  0.0  0.53  0.0  1.0
  Be  Be0  1  0.0  0.0  0.0  1.0
  Se  Se2  1  0.0  0.98  0.79  1.0
  Se  Se3  1  0.73  0.55  0.0  1.0

data_MgBeSe2
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.46
_cell_length_b   5.46
_cell_length_c   5.46
_cell_angle_alpha   80.51
_cell_angle_beta   71.52
_cell_angle_gamma   71.52
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgBeSe2
_chemical_formula_sum   'Mg1 Be1 Se2'
_cell_volume   92.47
_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
  Mg  Mg0  1  0.53  0.0  0.47  1.0
  Be  Be1  1  0.0  0.0  0.0  1.0
  Se  Se2  1  0.55  0.27  0.45  1.0
  Se  Se3  1  0.98  0.0  0.81  1.0

Mg Be Se Se