data_LiFeSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.84
_cell_length_b   3.84
_cell_length_c   3.84
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   LiFeSi
_chemical_formula_sum   'Li1 Fe1 Si1'
_cell_volume   40.01
_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  0.0  0.0  0.0  1.0
  Fe  Fe0  1  0.71  0.71  0.71  1.0
  Si  Si2  1  0.36  0.36  0.36  1.0

data_LiFeSi
_symmetry_space_group_name_H-M   R3m
_cell_length_a   3.84
_cell_length_b   3.84
_cell_length_c   9.4
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   LiFeSi
_chemical_formula_sum   'Li3 Fe3 Si3'
_cell_volume   120.04
_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
  Fe  Fe1  3  0.0  0.0  0.29  1.0
  Si  Si2  3  0.0  0.0  0.64  1.0

Li Fe Si
Li Fe Si 0 1 - - o 0 1 - o - 0 1 o - - 0 2 - o o 0 2 o - o 0 2 o o - 1 2 o o + 1 2 o + o 1 2 + o o 
LiFeSi crystallizes in the trigonal R3m space group. Li(1) is bonded to four equivalent Fe(1) and three equivalent Si(1) atoms to form LiFe4Si3 hexagonal pyramids that share corners with three equivalent Fe(1)Li4Si3 hexagonal pyramids, corners with six equivalent Li(1)Fe4Si3 hexagonal pyramids, edges with three equivalent Fe(1)Li4Si3 hexagonal pyramids, and edges with six equivalent Li(1)Fe4Si3 hexagonal pyramids. There are three shorter (2.26 Å) and one longer (2.68 Å) Li(1)-Fe(1) bond length. All Li(1)-Si(1) bond lengths are 2.23 Å. Fe(1) is bonded to four equivalent Li(1) and three equivalent Si(1) atoms to form distorted FeLi4Si3 hexagonal pyramids that share corners with three equivalent Li(1)Fe4Si3 hexagonal pyramids, corners with six equivalent Fe(1)Li4Si3 hexagonal pyramids, edges with three equivalent Li(1)Fe4Si3 hexagonal pyramids, and edges with six equivalent Fe(1)Li4Si3 hexagonal pyramids. All Fe(1)-Si(1) bond lengths are 2.23 Å. Si(1) is bonded in a distorted hexagonal planar geometry to three equivalent Li(1) and three equivalent Fe(1) atoms.