data_Li2BeSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.36
_cell_length_b   3.36
_cell_length_c   5.34
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Li2BeSe
_chemical_formula_sum   'Li2 Be1 Se1'
_cell_volume   60.27
_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
  Li  Li1  1  0.68  0.68  0.27  1.0
  Li  Li2  1  0.0  0.0  0.41  1.0
  Be  Be0  1  0.0  0.0  0.89  1.0
  Se  Se3  1  0.68  0.68  0.79  1.0

data_Li2BeSe
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.75
_cell_length_b   4.75
_cell_length_c   5.34
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Li2BeSe
_chemical_formula_sum   'Li4 Be2 Se2'
_cell_volume   120.54
_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
  Li  Li0  2  0.0  0.0  0.41  1.0
  Li  Li1  2  0.18  0.5  0.27  1.0
  Be  Be2  2  0.0  0.0  0.89  1.0
  Se  Se3  2  0.18  0.5  0.79  1.0

Li Li Be Se
Li2BeSe crystallizes in the monoclinic Cm space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 6-coordinate geometry to three equivalent Li(2), one Be(1), and two equivalent Se(1) atoms. There is one shorter (1.71 Å) and two longer (2.64 Å) Li(1)-Li(2) bond lengths. The Li(1)-Be(1) bond length is 2.51 Å. There is one shorter (2.57 Å) and one longer (2.78 Å) Li(1)-Se(1) bond length. In the second Li site, Li(2) is bonded in a 3-coordinate geometry to three equivalent Li(1), one Be(1), and one Se(1) atom. The Li(2)-Be(1) bond length is 2.57 Å. The Li(2)-Se(1) bond length is 2.51 Å. Be(1) is bonded in a distorted single-bond geometry to one Li(1), one Li(2), and one Se(1) atom. The Be(1)-Se(1) bond length is 1.63 Å. Se(1) is bonded in a distorted single-bond geometry to one Li(2), two equivalent Li(1), and one Be(1) atom.