data_Li2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.1
_cell_length_b   4.1
_cell_length_c   3.53
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Li2Se
_chemical_formula_sum   'Li2 Se1'
_cell_volume   59.25
_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  Li0  1  0.0  0.05  0.76  1.0
  Li  Li1  1  0.05  0.0  0.76  1.0
  Se  Se2  1  0.0  0.0  0.0  1.0

data_Li2Se
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.8
_cell_length_b   5.8
_cell_length_c   3.53
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Li2Se
_chemical_formula_sum   'Li4 Se2'
_cell_volume   118.51
_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  4  0.02  0.02  0.76  1.0
  Se  Se1  2  0.0  0.0  0.0  1.0

Li Li Se
Li2Se is alpha Po structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Li2Se clusters. Li(1) is bonded in a distorted L-shaped geometry to one Li(1) and one Se(1) atom. The Li(1)-Li(1) bond length is 0.29 Å. The Li(1)-Se(1) bond length is 0.86 Å. Se(1) is bonded in a 2-coordinate geometry to two equivalent Li(1) atoms.