data_LiMg2Bi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.18
_cell_length_b   5.18
_cell_length_c   5.18
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   LiMg2Bi
_chemical_formula_sum   'Li1 Mg2 Bi1'
_cell_volume   98.32
_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
  Mg  Mg2  1  0.5  0.5  0.5  1.0
  Mg  Mg3  1  0.83  0.83  0.83  1.0
  Bi  Bi0  1  0.66  0.66  0.66  1.0

data_LiMg2Bi
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.18
_cell_length_b   5.18
_cell_length_c   12.69
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   LiMg2Bi
_chemical_formula_sum   'Li3 Mg6 Bi3'
_cell_volume   294.97
_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
  Mg  Mg1  3  0.0  0.0  0.17  1.0
  Mg  Mg2  3  0.0  0.0  0.5  1.0
  Bi  Bi3  3  0.0  0.0  0.34  1.0

Li Mg Mg Bi
LiMg2Bi crystallizes in the trigonal R3m space group. Li(1) is bonded to one Mg(2) and three equivalent Bi(1) atoms to form LiMgBi3 trigonal pyramids that share  a cornercorner with one Bi(1)Li3Mg2 trigonal bipyramid and corners with six equivalent Li(1)MgBi3 trigonal pyramids. The Li(1)-Mg(2) bond length is 2.14 Å. All Li(1)-Bi(1) bond lengths are 2.99 Å. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a single-bond geometry to one Bi(1) atom. The Mg(1)-Bi(1) bond length is 2.14 Å. In the second Mg site, Mg(2) is bonded in a distorted linear geometry to one Li(1) and one Bi(1) atom. The Mg(2)-Bi(1) bond length is 2.14 Å. Bi(1) is bonded to three equivalent Li(1), one Mg(1), and one Mg(2) atom to form distorted BiLi3Mg2 trigonal bipyramids that share corners with six equivalent Bi(1)Li3Mg2 trigonal bipyramids and  a cornercorner with one Li(1)MgBi3 trigonal pyramid.