data_MgBe2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.25
_cell_length_b   3.25
_cell_length_c   5.7
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgBe2Se
_chemical_formula_sum   'Mg1 Be2 Se1'
_cell_volume   60.24
_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  Mg2  1  0.0  0.0  0.68  1.0
  Be  Be0  1  0.0  0.0  0.7  1.0
  Be  Be1  1  0.62  0.62  0.18  1.0
  Se  Se3  1  0.62  0.62  0.71  1.0

data_MgBe2Se
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.6
_cell_length_b   4.6
_cell_length_c   5.7
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   MgBe2Se
_chemical_formula_sum   'Mg2 Be4 Se2'
_cell_volume   120.49
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.68  1.0
  Be  Be1  2  0.0  0.0  0.7  1.0
  Be  Be2  2  0.12  0.5  0.18  1.0
  Se  Se3  2  0.12  0.5  0.71  1.0

Mg Be Be Se
Mg Be Be Se 0 1 o o o 0 2 o - + 0 2 o - o 0 2 - o + 0 2 - o o 0 2 - - + 0 2 - - o 0 3 - - o 1 2 o - + 1 2 o - o 1 2 - o + 1 2 - o o 1 2 - - + 1 2 - - o 1 3 - - o 2 2 + o o 2 2 o + o 2 3 o o - 2 3 o o o 