The structure described by GeSi7 is Moissanite 9R-like structured and crystallizes in the cubic P-43m space group. Ge(1) is bonded to four equivalent Si(1) atoms to form GeSi4 tetrahedra that share corners with twelve equivalent Si(2)Si4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one Ge(1) and three equivalent Si(2) atoms to form corner-sharing SiSi3Ge tetrahedra. In the second Si site, Si(2) is bonded to four equivalent Si(1) atoms to form SiSi4 tetrahedra that share corners with four equivalent Ge(1)Si4 tetrahedra and corners with eight equivalent Si(2)Si4 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Si7Ge
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.465
_cell_length_b   5.465
_cell_length_c   5.465
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   163.254
_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
  Si  Si0  1  0.253  0.253  0.253  1.0
  Si  Si1  1  0.000  0.500  0.500  1.0
  Si  Si2  1  0.500  0.500  0.000  1.0
  Si  Si3  1  0.500  0.000  0.500  1.0
  Si  Si4  1  0.747  0.253  0.747  1.0
  Si  Si5  1  0.747  0.747  0.253  1.0
  Si  Si6  1  0.253  0.747  0.747  1.0
  Ge  Ge7  1  0.000  0.000  0.000  1.0
[/CIF]
.
The structure described by GeSi7 is Moissanite 9R-like structured and crystallizes in the cubic P-43m space group. Ge(1) is bonded to four equivalent Si(1) atoms to form GeSi4 tetrahedra that share corners with twelve equivalent Si(2)Si4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one Ge(1) and three equivalent Si(2) atoms to form corner-sharing SiSi3Ge tetrahedra. In the second Si site, Si(2) is bonded to four equivalent Si(1) atoms to form SiSi4 tetrahedra that share corners with four equivalent Ge(1)Si4 tetrahedra and corners with eight equivalent Si(2)Si4 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Si7Ge
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.465
_cell_length_b   5.465
_cell_length_c   5.465
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   163.254
_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
  Si  Si0  1  0.253  0.253  0.253  1.0
  Si  Si1  1  0.000  0.500  0.500  1.0
  Si  Si2  1  0.500  0.500  0.000  1.0
  Si  Si3  1  0.500  0.000  0.500  1.0
  Si  Si4  1  0.747  0.253  0.747  1.0
  Si  Si5  1  0.747  0.747  0.253  1.0
  Si  Si6  1  0.253  0.747  0.747  1.0
  Ge  Ge7  1  0.000  0.000  0.000  1.0
[/CIF]
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