The material described by MgLi2 crystallizes in the trigonal R32 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent Li(2); six equivalent Li(1); and four Mg(1,1,1) atoms to form LiLi8Mg4 cuboctahedra that share corners with eighteen Li(1,1,1)Li8Mg4 cuboctahedra; edges with four equivalent Li(2)Li6Mg6 cuboctahedra; edges with six equivalent Li(1)Li8Mg4 cuboctahedra; edges with eight Mg(1,1,1)Li9Mg3 cuboctahedra; faces with four equivalent Li(2)Li6Mg6 cuboctahedra; faces with eight Li(1,1)Li8Mg4 cuboctahedra; and faces with eight Mg(1,1,1)Li9Mg3 cuboctahedra. In the second Li site, Li(2) is bonded to six Li(1,1,1) and six Mg(1,1) atoms to form distorted LiLi6Mg6 cuboctahedra that share corners with six equivalent Li(2)Li6Mg6 cuboctahedra; corners with twelve Mg(1,1)Li9Mg3 cuboctahedra; edges with six equivalent Li(2)Li6Mg6 cuboctahedra; edges with twelve Li(1,1,1)Li8Mg4 cuboctahedra; faces with eight Mg(1,1,1)Li9Mg3 cuboctahedra; and faces with twelve Li(1,1,1)Li8Mg4 cuboctahedra. In the third Li site, Li(1) is bonded to two equivalent Li(2); six equivalent Li(1); and four Mg(1,1) atoms to form LiLi8Mg4 cuboctahedra that share corners with eighteen Li(1,1)Li8Mg4 cuboctahedra; edges with four equivalent Li(2)Li6Mg6 cuboctahedra; edges with six equivalent Li(1)Li8Mg4 cuboctahedra; edges with eight Mg(1,1)Li9Mg3 cuboctahedra; faces with four equivalent Li(2)Li6Mg6 cuboctahedra; faces with eight Li(1,1)Li8Mg4 cuboctahedra; and faces with eight Mg(1,1)Li9Mg3 cuboctahedra. In the fourth Li site, Li(1) is bonded to two equivalent Li(2); six Li(1,1); and four Mg(1,1) atoms to form LiLi8Mg4 cuboctahedra that share corners with eighteen Li(1,1,1)Li8Mg4 cuboctahedra; edges with four equivalent Li(2)Li6Mg6 cuboctahedra; edges with six equivalent Li(1)Li8Mg4 cuboctahedra; edges with eight Mg(1,1)Li9Mg3 cuboctahedra; faces with four equivalent Li(2)Li6Mg6 cuboctahedra; faces with eight Li(1,1,1)Li8Mg4 cuboctahedra; and faces with eight Mg(1,1)Li9Mg3 cuboctahedra. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to three equivalent Li(2); six Li(1,1,1); and three equivalent Mg(1) atoms to form MgLi9Mg3 cuboctahedra that share corners with six equivalent Li(2)Li6Mg6 cuboctahedra; corners with twelve Mg(1,1,1)Li9Mg3 cuboctahedra; edges with six equivalent Mg(1)Li9Mg3 cuboctahedra; edges with twelve Li(1,1,1)Li8Mg4 cuboctahedra; faces with four equivalent Li(2)Li6Mg6 cuboctahedra; faces with four equivalent Mg(1)Li9Mg3 cuboctahedra; and faces with twelve Li(1,1,1)Li8Mg4 cuboctahedra. In the second Mg site, Mg(1) is bonded to three equivalent Li(2); six Li(1,1,1); and three equivalent Mg(1) atoms to form MgLi9Mg3 cuboctahedra that share corners with six equivalent Li(2)Li6Mg6 cuboctahedra; corners with twelve Mg(1,1,1)Li9Mg3 cuboctahedra; edges with six equivalent Mg(1)Li9Mg3 cuboctahedra; edges with twelve Li(1,1,1)Li8Mg4 cuboctahedra; faces with four equivalent Li(2)Li6Mg6 cuboctahedra; faces with four Mg(1,1)Li9Mg3 cuboctahedra; and faces with twelve Li(1,1,1)Li8Mg4 cuboctahedra. In the third Mg site, Mg(1) is bonded to three equivalent Li(2); six Li(1,1); and three equivalent Mg(1) atoms to form MgLi9Mg3 cuboctahedra that share corners with six equivalent Li(2)Li6Mg6 cuboctahedra; corners with twelve Mg(1,1)Li9Mg3 cuboctahedra; edges with six equivalent Mg(1)Li9Mg3 cuboctahedra; edges with twelve Li(1,1)Li8Mg4 cuboctahedra; faces with four equivalent Li(2)Li6Mg6 cuboctahedra; faces with four Mg(1,1)Li9Mg3 cuboctahedra; and faces with twelve Li(1,1)Li8Mg4 cuboctahedra. is represented by the CIF file [CIF]
data_Li2Mg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.927
_cell_length_b   5.927
_cell_length_c   5.927
_cell_angle_alpha   53.101
_cell_angle_beta   53.101
_cell_angle_gamma   53.101
_symmetry_Int_Tables_number   1
_cell_volume   123.456
_cell_formula_units_Z   2
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  0.332  0.000  0.668  1.0
  Li  Li1  1  0.668  0.332  0.000  1.0
  Li  Li2  1  0.000  0.668  0.332  1.0
  Li  Li3  1  0.500  0.500  0.500  1.0
  Mg  Mg4  1  0.833  0.833  0.833  1.0
  Mg  Mg5  1  0.167  0.167  0.167  1.0
[/CIF]
.
The material described by MgLi2 crystallizes in the trigonal R32 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent Li(2); six equivalent Li(1); and four Mg(1,1,1) atoms to form LiLi8Mg4 cuboctahedra that share corners with eighteen Li(1,1,1)Li8Mg4 cuboctahedra; edges with four equivalent Li(2)Li6Mg6 cuboctahedra; edges with six equivalent Li(1)Li8Mg4 cuboctahedra; edges with eight Mg(1,1,1)Li9Mg3 cuboctahedra; faces with four equivalent Li(2)Li6Mg6 cuboctahedra; faces with eight Li(1,1)Li8Mg4 cuboctahedra; and faces with eight Mg(1,1,1)Li9Mg3 cuboctahedra. In the second Li site, Li(2) is bonded to six Li(1,1,1) and six Mg(1,1) atoms to form distorted LiLi6Mg6 cuboctahedra that share corners with six equivalent Li(2)Li6Mg6 cuboctahedra; corners with twelve Mg(1,1)Li9Mg3 cuboctahedra; edges with six equivalent Li(2)Li6Mg6 cuboctahedra; edges with twelve Li(1,1,1)Li8Mg4 cuboctahedra; faces with eight Mg(1,1,1)Li9Mg3 cuboctahedra; and faces with twelve Li(1,1,1)Li8Mg4 cuboctahedra. In the third Li site, Li(1) is bonded to two equivalent Li(2); six equivalent Li(1); and four Mg(1,1) atoms to form LiLi8Mg4 cuboctahedra that share corners with eighteen Li(1,1)Li8Mg4 cuboctahedra; edges with four equivalent Li(2)Li6Mg6 cuboctahedra; edges with six equivalent Li(1)Li8Mg4 cuboctahedra; edges with eight Mg(1,1)Li9Mg3 cuboctahedra; faces with four equivalent Li(2)Li6Mg6 cuboctahedra; faces with eight Li(1,1)Li8Mg4 cuboctahedra; and faces with eight Mg(1,1)Li9Mg3 cuboctahedra. In the fourth Li site, Li(1) is bonded to two equivalent Li(2); six Li(1,1); and four Mg(1,1) atoms to form LiLi8Mg4 cuboctahedra that share corners with eighteen Li(1,1,1)Li8Mg4 cuboctahedra; edges with four equivalent Li(2)Li6Mg6 cuboctahedra; edges with six equivalent Li(1)Li8Mg4 cuboctahedra; edges with eight Mg(1,1)Li9Mg3 cuboctahedra; faces with four equivalent Li(2)Li6Mg6 cuboctahedra; faces with eight Li(1,1,1)Li8Mg4 cuboctahedra; and faces with eight Mg(1,1)Li9Mg3 cuboctahedra. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to three equivalent Li(2); six Li(1,1,1); and three equivalent Mg(1) atoms to form MgLi9Mg3 cuboctahedra that share corners with six equivalent Li(2)Li6Mg6 cuboctahedra; corners with twelve Mg(1,1,1)Li9Mg3 cuboctahedra; edges with six equivalent Mg(1)Li9Mg3 cuboctahedra; edges with twelve Li(1,1,1)Li8Mg4 cuboctahedra; faces with four equivalent Li(2)Li6Mg6 cuboctahedra; faces with four equivalent Mg(1)Li9Mg3 cuboctahedra; and faces with twelve Li(1,1,1)Li8Mg4 cuboctahedra. In the second Mg site, Mg(1) is bonded to three equivalent Li(2); six Li(1,1,1); and three equivalent Mg(1) atoms to form MgLi9Mg3 cuboctahedra that share corners with six equivalent Li(2)Li6Mg6 cuboctahedra; corners with twelve Mg(1,1,1)Li9Mg3 cuboctahedra; edges with six equivalent Mg(1)Li9Mg3 cuboctahedra; edges with twelve Li(1,1,1)Li8Mg4 cuboctahedra; faces with four equivalent Li(2)Li6Mg6 cuboctahedra; faces with four Mg(1,1)Li9Mg3 cuboctahedra; and faces with twelve Li(1,1,1)Li8Mg4 cuboctahedra. In the third Mg site, Mg(1) is bonded to three equivalent Li(2); six Li(1,1); and three equivalent Mg(1) atoms to form MgLi9Mg3 cuboctahedra that share corners with six equivalent Li(2)Li6Mg6 cuboctahedra; corners with twelve Mg(1,1)Li9Mg3 cuboctahedra; edges with six equivalent Mg(1)Li9Mg3 cuboctahedra; edges with twelve Li(1,1)Li8Mg4 cuboctahedra; faces with four equivalent Li(2)Li6Mg6 cuboctahedra; faces with four Mg(1,1)Li9Mg3 cuboctahedra; and faces with twelve Li(1,1)Li8Mg4 cuboctahedra. is represented by the CIF file [CIF]
data_Li2Mg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.927
_cell_length_b   5.927
_cell_length_c   5.927
_cell_angle_alpha   53.101
_cell_angle_beta   53.101
_cell_angle_gamma   53.101
_symmetry_Int_Tables_number   1
_cell_volume   123.456
_cell_formula_units_Z   2
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  0.332  0.000  0.668  1.0
  Li  Li1  1  0.668  0.332  0.000  1.0
  Li  Li2  1  0.000  0.668  0.332  1.0
  Li  Li3  1  0.500  0.500  0.500  1.0
  Mg  Mg4  1  0.833  0.833  0.833  1.0
  Mg  Mg5  1  0.167  0.167  0.167  1.0
[/CIF]
.