The compound described by Mg6SnSi crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Sn(1), and two equivalent Si(1) atoms to form distorted MgMg8Si2Sn2 cuboctahedra that share corners with ten equivalent Mg(1)Mg8Si2Sn2 cuboctahedra, edges with two equivalent Mg(1)Mg8Si2Sn2 cuboctahedra, edges with four equivalent Mg(4)Mg4Si2 cuboctahedra, and faces with four equivalent Mg(1)Mg8Si2Sn2 cuboctahedra. In the second Mg site, Mg(2) is bonded in a distorted linear geometry to four equivalent Mg(1) and two equivalent Sn(1) atoms. In the third Mg site, Mg(3) is bonded in a 3-coordinate geometry to two equivalent Mg(1), two equivalent Sn(1), and one Si(1) atom. In the fourth Mg site, Mg(4) is bonded to four equivalent Mg(1) and two equivalent Si(1) atoms to form distorted MgMg4Si2 cuboctahedra that share corners with two equivalent Mg(4)Mg4Si2 cuboctahedra, edges with two equivalent Mg(4)Mg4Si2 cuboctahedra, and edges with eight equivalent Mg(1)Mg8Si2Sn2 cuboctahedra. Sn(1) is bonded in a distorted q6 geometry to two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms. Si(1) is bonded in a 8-coordinate geometry to two equivalent Mg(3), two equivalent Mg(4), and four equivalent Mg(1) atoms. is represented by the CIF file [CIF]
data_Mg6SiSn
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.154
_cell_length_b   6.084
_cell_length_c   6.290
_cell_angle_alpha   118.921
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   172.631
_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
  Mg  Mg0  1  1.000  0.832  0.184  1.0
  Mg  Mg1  1  1.000  0.352  0.184  1.0
  Mg  Mg2  1  1.000  0.332  0.664  1.0
  Mg  Mg3  1  0.500  0.666  0.833  1.0
  Mg  Mg4  1  0.500  0.167  0.833  1.0
  Mg  Mg5  1  0.500  0.169  0.338  1.0
  Si  Si6  1  0.500  0.641  0.282  1.0
  Sn  Sn7  1  1.000  0.841  0.683  1.0
[/CIF]
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The compound described by Mg6SnSi crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Sn(1), and two equivalent Si(1) atoms to form distorted MgMg8Si2Sn2 cuboctahedra that share corners with ten equivalent Mg(1)Mg8Si2Sn2 cuboctahedra, edges with two equivalent Mg(1)Mg8Si2Sn2 cuboctahedra, edges with four equivalent Mg(4)Mg4Si2 cuboctahedra, and faces with four equivalent Mg(1)Mg8Si2Sn2 cuboctahedra. In the second Mg site, Mg(2) is bonded in a distorted linear geometry to four equivalent Mg(1) and two equivalent Sn(1) atoms. In the third Mg site, Mg(3) is bonded in a 3-coordinate geometry to two equivalent Mg(1), two equivalent Sn(1), and one Si(1) atom. In the fourth Mg site, Mg(4) is bonded to four equivalent Mg(1) and two equivalent Si(1) atoms to form distorted MgMg4Si2 cuboctahedra that share corners with two equivalent Mg(4)Mg4Si2 cuboctahedra, edges with two equivalent Mg(4)Mg4Si2 cuboctahedra, and edges with eight equivalent Mg(1)Mg8Si2Sn2 cuboctahedra. Sn(1) is bonded in a distorted q6 geometry to two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms. Si(1) is bonded in a 8-coordinate geometry to two equivalent Mg(3), two equivalent Mg(4), and four equivalent Mg(1) atoms. is represented by the CIF file [CIF]
data_Mg6SiSn
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.154
_cell_length_b   6.084
_cell_length_c   6.290
_cell_angle_alpha   118.921
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   172.631
_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
  Mg  Mg0  1  1.000  0.832  0.184  1.0
  Mg  Mg1  1  1.000  0.352  0.184  1.0
  Mg  Mg2  1  1.000  0.332  0.664  1.0
  Mg  Mg3  1  0.500  0.666  0.833  1.0
  Mg  Mg4  1  0.500  0.167  0.833  1.0
  Mg  Mg5  1  0.500  0.169  0.338  1.0
  Si  Si6  1  0.500  0.641  0.282  1.0
  Sn  Sn7  1  1.000  0.841  0.683  1.0
[/CIF]
.