The material structure described by Ca7Mg6Si14 crystallizes in the hexagonal P6/mmm space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 13-coordinate geometry to four equivalent Mg(1), one Si(3), four equivalent Si(1), and four equivalent Si(2) atoms. In the second Ca site, Ca(2) is bonded to twelve equivalent Si(2) atoms to form face-sharing CaSi12 cuboctahedra. Mg(1) is bonded to four equivalent Ca(1), two equivalent Si(1), and two equivalent Si(3) atoms to form a mixture of distorted face and edge-sharing MgCa4Si4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 7-coordinate geometry to four equivalent Ca(1), two equivalent Mg(1), and one Si(2) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Ca(2), four equivalent Ca(1), one Si(1), and two equivalent Si(2) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to three equivalent Ca(1) and six equivalent Mg(1) atoms. is represented by the CIF card [CIF]
data_Ca7(Mg3Si7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.215
_cell_length_b   12.934
_cell_length_c   12.934
_cell_angle_alpha   120.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   610.725
_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
  Ca  Ca0  1  0.000  0.813  0.187  1.0
  Ca  Ca1  1  0.000  0.187  0.813  1.0
  Ca  Ca2  1  0.000  0.373  0.187  1.0
  Ca  Ca3  1  0.000  0.627  0.813  1.0
  Ca  Ca4  1  0.000  0.813  0.627  1.0
  Ca  Ca5  1  0.000  0.187  0.373  1.0
  Ca  Ca6  1  0.000  0.000  0.000  1.0
  Mg  Mg7  1  0.500  0.414  0.586  1.0
  Mg  Mg8  1  0.500  0.586  0.414  1.0
  Mg  Mg9  1  0.500  0.173  0.586  1.0
  Mg  Mg10  1  0.500  0.827  0.414  1.0
  Mg  Mg11  1  0.500  0.414  0.827  1.0
  Mg  Mg12  1  0.500  0.586  0.173  1.0
  Si  Si13  1  0.500  0.643  0.643  1.0
  Si  Si14  1  0.500  0.357  0.357  1.0
  Si  Si15  1  0.500  0.000  0.357  1.0
  Si  Si16  1  0.500  0.000  0.643  1.0
  Si  Si17  1  0.500  0.357  0.000  1.0
  Si  Si18  1  0.500  0.643  0.000  1.0
  Si  Si19  1  0.500  0.819  0.819  1.0
  Si  Si20  1  0.500  0.181  0.181  1.0
  Si  Si21  1  0.500  0.000  0.181  1.0
  Si  Si22  1  0.500  0.000  0.819  1.0
  Si  Si23  1  0.500  0.181  0.000  1.0
  Si  Si24  1  0.500  0.819  0.000  1.0
  Si  Si25  1  0.000  0.667  0.333  1.0
  Si  Si26  1  0.000  0.333  0.667  1.0
[/CIF]
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The material structure described by Ca7Mg6Si14 crystallizes in the hexagonal P6/mmm space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 13-coordinate geometry to four equivalent Mg(1), one Si(3), four equivalent Si(1), and four equivalent Si(2) atoms. In the second Ca site, Ca(2) is bonded to twelve equivalent Si(2) atoms to form face-sharing CaSi12 cuboctahedra. Mg(1) is bonded to four equivalent Ca(1), two equivalent Si(1), and two equivalent Si(3) atoms to form a mixture of distorted face and edge-sharing MgCa4Si4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 7-coordinate geometry to four equivalent Ca(1), two equivalent Mg(1), and one Si(2) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Ca(2), four equivalent Ca(1), one Si(1), and two equivalent Si(2) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to three equivalent Ca(1) and six equivalent Mg(1) atoms. is represented by the CIF card [CIF]
data_Ca7(Mg3Si7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.215
_cell_length_b   12.934
_cell_length_c   12.934
_cell_angle_alpha   120.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   610.725
_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
  Ca  Ca0  1  0.000  0.813  0.187  1.0
  Ca  Ca1  1  0.000  0.187  0.813  1.0
  Ca  Ca2  1  0.000  0.373  0.187  1.0
  Ca  Ca3  1  0.000  0.627  0.813  1.0
  Ca  Ca4  1  0.000  0.813  0.627  1.0
  Ca  Ca5  1  0.000  0.187  0.373  1.0
  Ca  Ca6  1  0.000  0.000  0.000  1.0
  Mg  Mg7  1  0.500  0.414  0.586  1.0
  Mg  Mg8  1  0.500  0.586  0.414  1.0
  Mg  Mg9  1  0.500  0.173  0.586  1.0
  Mg  Mg10  1  0.500  0.827  0.414  1.0
  Mg  Mg11  1  0.500  0.414  0.827  1.0
  Mg  Mg12  1  0.500  0.586  0.173  1.0
  Si  Si13  1  0.500  0.643  0.643  1.0
  Si  Si14  1  0.500  0.357  0.357  1.0
  Si  Si15  1  0.500  0.000  0.357  1.0
  Si  Si16  1  0.500  0.000  0.643  1.0
  Si  Si17  1  0.500  0.357  0.000  1.0
  Si  Si18  1  0.500  0.643  0.000  1.0
  Si  Si19  1  0.500  0.819  0.819  1.0
  Si  Si20  1  0.500  0.181  0.181  1.0
  Si  Si21  1  0.500  0.000  0.181  1.0
  Si  Si22  1  0.500  0.000  0.819  1.0
  Si  Si23  1  0.500  0.181  0.000  1.0
  Si  Si24  1  0.500  0.819  0.000  1.0
  Si  Si25  1  0.000  0.667  0.333  1.0
  Si  Si26  1  0.000  0.333  0.667  1.0
[/CIF]
.