The crystal structure described by Ca2Mg3Si crystallizes in the hexagonal P6_3/mmc space group. Ca(1) is bonded in a 16-coordinate geometry to four equivalent Ca(1), nine equivalent Mg(1), and three equivalent Si(1) atoms. Mg(1) is bonded to six equivalent Ca(1), four equivalent Mg(1), and two equivalent Si(1) atoms to form distorted MgCa6Mg4Si2 cuboctahedra that share corners with four equivalent Si(1)Ca6Mg6 cuboctahedra, corners with fourteen equivalent Mg(1)Ca6Mg4Si2 cuboctahedra, edges with six equivalent Mg(1)Ca6Mg4Si2 cuboctahedra, faces with six equivalent Si(1)Ca6Mg6 cuboctahedra, and faces with twelve equivalent Mg(1)Ca6Mg4Si2 cuboctahedra. Si(1) is bonded to six equivalent Ca(1) and six equivalent Mg(1) atoms to form distorted SiCa6Mg6 cuboctahedra that share corners with twelve equivalent Mg(1)Ca6Mg4Si2 cuboctahedra, edges with six equivalent Si(1)Ca6Mg6 cuboctahedra, faces with two equivalent Si(1)Ca6Mg6 cuboctahedra, and faces with eighteen equivalent Mg(1)Ca6Mg4Si2 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2Mg3Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.057
_cell_length_b   6.057
_cell_length_c   9.462
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   300.573
_cell_formula_units_Z   2
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  0.333  0.667  0.941  1.0
  Ca  Ca1  1  0.667  0.333  0.059  1.0
  Ca  Ca2  1  0.667  0.333  0.441  1.0
  Ca  Ca3  1  0.333  0.667  0.559  1.0
  Mg  Mg4  1  0.165  0.835  0.250  1.0
  Mg  Mg5  1  0.165  0.330  0.250  1.0
  Mg  Mg6  1  0.670  0.835  0.250  1.0
  Mg  Mg7  1  0.835  0.165  0.750  1.0
  Mg  Mg8  1  0.835  0.670  0.750  1.0
  Mg  Mg9  1  0.330  0.165  0.750  1.0
  Si  Si10  1  0.000  0.000  0.500  1.0
  Si  Si11  1  0.000  0.000  0.000  1.0
[/CIF]
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The crystal structure described by Ca2Mg3Si crystallizes in the hexagonal P6_3/mmc space group. Ca(1) is bonded in a 16-coordinate geometry to four equivalent Ca(1), nine equivalent Mg(1), and three equivalent Si(1) atoms. Mg(1) is bonded to six equivalent Ca(1), four equivalent Mg(1), and two equivalent Si(1) atoms to form distorted MgCa6Mg4Si2 cuboctahedra that share corners with four equivalent Si(1)Ca6Mg6 cuboctahedra, corners with fourteen equivalent Mg(1)Ca6Mg4Si2 cuboctahedra, edges with six equivalent Mg(1)Ca6Mg4Si2 cuboctahedra, faces with six equivalent Si(1)Ca6Mg6 cuboctahedra, and faces with twelve equivalent Mg(1)Ca6Mg4Si2 cuboctahedra. Si(1) is bonded to six equivalent Ca(1) and six equivalent Mg(1) atoms to form distorted SiCa6Mg6 cuboctahedra that share corners with twelve equivalent Mg(1)Ca6Mg4Si2 cuboctahedra, edges with six equivalent Si(1)Ca6Mg6 cuboctahedra, faces with two equivalent Si(1)Ca6Mg6 cuboctahedra, and faces with eighteen equivalent Mg(1)Ca6Mg4Si2 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2Mg3Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.057
_cell_length_b   6.057
_cell_length_c   9.462
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   300.573
_cell_formula_units_Z   2
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  0.333  0.667  0.941  1.0
  Ca  Ca1  1  0.667  0.333  0.059  1.0
  Ca  Ca2  1  0.667  0.333  0.441  1.0
  Ca  Ca3  1  0.333  0.667  0.559  1.0
  Mg  Mg4  1  0.165  0.835  0.250  1.0
  Mg  Mg5  1  0.165  0.330  0.250  1.0
  Mg  Mg6  1  0.670  0.835  0.250  1.0
  Mg  Mg7  1  0.835  0.165  0.750  1.0
  Mg  Mg8  1  0.835  0.670  0.750  1.0
  Mg  Mg9  1  0.330  0.165  0.750  1.0
  Si  Si10  1  0.000  0.000  0.500  1.0
  Si  Si11  1  0.000  0.000  0.000  1.0
[/CIF]
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