data_Li2Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.83
_cell_length_b   4.83
_cell_length_c   4.83
_cell_angle_alpha   141.76
_cell_angle_beta   141.76
_cell_angle_gamma   55.2
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Li2Si
_chemical_formula_sum   'Li2 Si1'
_cell_volume   42.79
_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  0.0  0.69  1.0
  Li  Li1  1  0.0  0.0  0.86  1.0
  Si  Si2  1  0.0  0.0  0.0  1.0

data_Li2Si
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.47
_cell_length_b   4.47
_cell_length_c   4.83
_cell_angle_alpha   90.0
_cell_angle_beta   117.6
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Li2Si
_chemical_formula_sum   'Li4 Si2'
_cell_volume   85.57
_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  0.14  1.0
  Li  Li1  2  0.0  0.0  0.31  1.0
  Si  Si2  2  0.0  0.0  0.0  1.0

Li Li Si
Li Li Si 0 1 o o o 1 2 o o + 
Li2Si crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Li2Si clusters. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a single-bond geometry to one Li(2) atom. The Li(1)-Li(2) bond length is 0.83 Å. In the second Li site, Li(2) is bonded in a distorted single-bond geometry to one Li(1) and one Si(1) atom. The Li(2)-Si(1) bond length is 0.66 Å. Si(1) is bonded in a single-bond geometry to one Li(2) atom.