The compound described by Li2Mg3Si2 crystallizes in the trigonal R3m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 11-coordinate geometry to three equivalent Li(2), one Mg(2), one Mg(3), three equivalent Mg(1), and three equivalent Si(1) atoms. In the second Li site, Li(2) is bonded to three equivalent Li(1), one Si(2), and three equivalent Si(1) atoms to form distorted edge-sharing LiLi3Si4 tetrahedra. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 7-coordinate geometry to three equivalent Li(1), one Si(1), and three equivalent Si(2) atoms. In the second Mg site, Mg(2) is bonded in a 5-coordinate geometry to one Li(1), one Si(2), and three equivalent Si(1) atoms. In the third Mg site, Mg(3) is bonded in a 5-coordinate geometry to one Li(1), one Si(1), and three equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a distorted body-centered cubic geometry to three equivalent Li(1), three equivalent Li(2), one Mg(1), one Mg(3), and three equivalent Mg(2) atoms. In the second Si site, Si(2) is bonded in a body-centered cubic geometry to one Li(2), one Mg(2), three equivalent Mg(1), and three equivalent Mg(3) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li2Mg3Si2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.778
_cell_length_b   7.778
_cell_length_c   7.778
_cell_angle_alpha   33.450
_cell_angle_beta   33.450
_cell_angle_gamma   33.450
_symmetry_Int_Tables_number   1
_cell_volume   127.298
_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  0.745  0.745  0.745  1.0
  Li  Li1  1  0.368  0.368  0.368  1.0
  Mg  Mg2  1  0.127  0.127  0.127  1.0
  Mg  Mg3  1  0.625  0.625  0.625  1.0
  Mg  Mg4  1  0.882  0.882  0.882  1.0
  Si  Si5  1  0.004  0.004  0.004  1.0
  Si  Si6  1  0.499  0.499  0.499  1.0
[/CIF]
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The compound described by Li2Mg3Si2 crystallizes in the trigonal R3m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 11-coordinate geometry to three equivalent Li(2), one Mg(2), one Mg(3), three equivalent Mg(1), and three equivalent Si(1) atoms. In the second Li site, Li(2) is bonded to three equivalent Li(1), one Si(2), and three equivalent Si(1) atoms to form distorted edge-sharing LiLi3Si4 tetrahedra. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 7-coordinate geometry to three equivalent Li(1), one Si(1), and three equivalent Si(2) atoms. In the second Mg site, Mg(2) is bonded in a 5-coordinate geometry to one Li(1), one Si(2), and three equivalent Si(1) atoms. In the third Mg site, Mg(3) is bonded in a 5-coordinate geometry to one Li(1), one Si(1), and three equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a distorted body-centered cubic geometry to three equivalent Li(1), three equivalent Li(2), one Mg(1), one Mg(3), and three equivalent Mg(2) atoms. In the second Si site, Si(2) is bonded in a body-centered cubic geometry to one Li(2), one Mg(2), three equivalent Mg(1), and three equivalent Mg(3) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li2Mg3Si2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.778
_cell_length_b   7.778
_cell_length_c   7.778
_cell_angle_alpha   33.450
_cell_angle_beta   33.450
_cell_angle_gamma   33.450
_symmetry_Int_Tables_number   1
_cell_volume   127.298
_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  0.745  0.745  0.745  1.0
  Li  Li1  1  0.368  0.368  0.368  1.0
  Mg  Mg2  1  0.127  0.127  0.127  1.0
  Mg  Mg3  1  0.625  0.625  0.625  1.0
  Mg  Mg4  1  0.882  0.882  0.882  1.0
  Si  Si5  1  0.004  0.004  0.004  1.0
  Si  Si6  1  0.499  0.499  0.499  1.0
[/CIF]
.