data_Li2LaSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.07
_cell_length_b   5.07
_cell_length_c   5.07
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Li2LaSe
_chemical_formula_sum   'Li2 La1 Se1'
_cell_volume   92.31
_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  0.38  0.38  0.38  1.0
  Li  Li2  1  0.0  0.0  0.0  1.0
  La  La0  1  0.79  0.79  0.79  1.0
  Se  Se3  1  0.59  0.59  0.59  1.0

data_Li2LaSe
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.07
_cell_length_b   5.07
_cell_length_c   12.43
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Li2LaSe
_chemical_formula_sum   'Li6 La3 Se3'
_cell_volume   276.92
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  3  0.0  0.0  0.0  1.0
  Li  Li1  3  0.0  0.0  0.62  1.0
  La  La2  3  0.0  0.0  0.21  1.0
  Se  Se3  3  0.0  0.0  0.41  1.0

Li Li La Se
Li Li La Se 0 3 o - o 0 3 - o o 0 3 o o - 0 3 o o o 0 1 o o + 0 1 o + o 0 1 + o o 0 2 - o o 0 2 o - o 0 2 o o - 1 2 - - - 1 2 - - o 1 2 o - - 1 2 - o - 1 3 - - o 1 3 - o - 1 3 o - - 2 3 o o o 2 3 o o + 2 3 + o o 2 3 o + o 
Li2LaSe crystallizes in the trigonal R3m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a single-bond geometry to one Se(1) atom. The Li(1)-Se(1) bond length is 2.57 Å. In the second Li site, Li(2) is bonded in a 4-coordinate geometry to one La(1) and three equivalent Se(1) atoms. The Li(2)-La(1) bond length is 2.57 Å. All Li(2)-Se(1) bond lengths are 3.09 Å. La(1) is bonded in a 1-coordinate geometry to one Li(2) and one Se(1) atom. The La(1)-Se(1) bond length is 2.57 Å. Se(1) is bonded in a distorted linear geometry to one Li(1), three equivalent Li(2), and one La(1) atom.