The material described by Mg4SnSi is alpha bismuth trifluoride-derived structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to three equivalent Sn(1) and one Si(1) atom to form MgSiSn3 tetrahedra that share corners with six equivalent Mg(2)Si3Sn tetrahedra, corners with ten equivalent Mg(1)SiSn3 tetrahedra, edges with three equivalent Mg(2)Si3Sn tetrahedra, and edges with three equivalent Mg(1)SiSn3 tetrahedra. In the second Mg site, Mg(2) is bonded to one Sn(1) and three equivalent Si(1) atoms to form MgSi3Sn tetrahedra that share corners with six equivalent Mg(1)SiSn3 tetrahedra, corners with ten equivalent Mg(2)Si3Sn tetrahedra, edges with three equivalent Mg(2)Si3Sn tetrahedra, and edges with three equivalent Mg(1)SiSn3 tetrahedra. Sn(1) is bonded in a body-centered cubic geometry to two equivalent Mg(2) and six equivalent Mg(1) atoms. Si(1) is bonded in a body-centered cubic geometry to two equivalent Mg(1) and six equivalent Mg(2) atoms. is represented by the CIF file [CIF]
data_Mg4SiSn
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.047
_cell_length_b   8.047
_cell_length_c   8.047
_cell_angle_alpha   33.721
_cell_angle_beta   33.721
_cell_angle_gamma   33.721
_symmetry_Int_Tables_number   1
_cell_volume   143.104
_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  0.622  0.622  0.622  1.0
  Mg  Mg1  1  0.128  0.128  0.128  1.0
  Mg  Mg2  1  0.872  0.872  0.872  1.0
  Mg  Mg3  1  0.378  0.378  0.378  1.0
  Si  Si4  1  0.500  0.500  0.500  1.0
  Sn  Sn5  1  0.000  0.000  0.000  1.0
[/CIF]
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The material described by Mg4SnSi is alpha bismuth trifluoride-derived structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to three equivalent Sn(1) and one Si(1) atom to form MgSiSn3 tetrahedra that share corners with six equivalent Mg(2)Si3Sn tetrahedra, corners with ten equivalent Mg(1)SiSn3 tetrahedra, edges with three equivalent Mg(2)Si3Sn tetrahedra, and edges with three equivalent Mg(1)SiSn3 tetrahedra. In the second Mg site, Mg(2) is bonded to one Sn(1) and three equivalent Si(1) atoms to form MgSi3Sn tetrahedra that share corners with six equivalent Mg(1)SiSn3 tetrahedra, corners with ten equivalent Mg(2)Si3Sn tetrahedra, edges with three equivalent Mg(2)Si3Sn tetrahedra, and edges with three equivalent Mg(1)SiSn3 tetrahedra. Sn(1) is bonded in a body-centered cubic geometry to two equivalent Mg(2) and six equivalent Mg(1) atoms. Si(1) is bonded in a body-centered cubic geometry to two equivalent Mg(1) and six equivalent Mg(2) atoms. is represented by the CIF file [CIF]
data_Mg4SiSn
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.047
_cell_length_b   8.047
_cell_length_c   8.047
_cell_angle_alpha   33.721
_cell_angle_beta   33.721
_cell_angle_gamma   33.721
_symmetry_Int_Tables_number   1
_cell_volume   143.104
_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  0.622  0.622  0.622  1.0
  Mg  Mg1  1  0.128  0.128  0.128  1.0
  Mg  Mg2  1  0.872  0.872  0.872  1.0
  Mg  Mg3  1  0.378  0.378  0.378  1.0
  Si  Si4  1  0.500  0.500  0.500  1.0
  Sn  Sn5  1  0.000  0.000  0.000  1.0
[/CIF]
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