The crystal structure described by Mg2Ca is Cubic Laves structured and crystallizes in the trigonal R-3m space group. Ca(1) is bonded in a 16-coordinate geometry to four equivalent Ca(1), three equivalent Mg(2), and nine equivalent Mg(1) atoms. There are two inequivalent Mg sites. In the first Mg site, Mg(2) is bonded to six equivalent Ca(1) and six equivalent Mg(1) atoms to form a mixture of corner, edge, and face-sharing MgCa6Mg6 cuboctahedra. In the second Mg site, Mg(1) is bonded to six equivalent Ca(1), two equivalent Mg(2), and four equivalent Mg(1) atoms to form a mixture of corner, edge, and face-sharing MgCa6Mg6 cuboctahedra. is represented by the CIF card [CIF]
data_CaMg2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.320
_cell_length_b   6.320
_cell_length_c   6.320
_cell_angle_alpha   58.046
_cell_angle_beta   58.046
_cell_angle_gamma   58.046
_symmetry_Int_Tables_number   1
_cell_volume   170.501
_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  0.876  0.876  0.876  1.0
  Ca  Ca1  1  0.124  0.124  0.124  1.0
  Mg  Mg2  1  0.500  0.000  0.500  1.0
  Mg  Mg3  1  0.000  0.500  0.500  1.0
  Mg  Mg4  1  0.500  0.500  0.500  1.0
  Mg  Mg5  1  0.500  0.500  0.000  1.0
[/CIF]
.
The crystal structure described by Mg2Ca is Cubic Laves structured and crystallizes in the trigonal R-3m space group. Ca(1) is bonded in a 16-coordinate geometry to four equivalent Ca(1), three equivalent Mg(2), and nine equivalent Mg(1) atoms. There are two inequivalent Mg sites. In the first Mg site, Mg(2) is bonded to six equivalent Ca(1) and six equivalent Mg(1) atoms to form a mixture of corner, edge, and face-sharing MgCa6Mg6 cuboctahedra. In the second Mg site, Mg(1) is bonded to six equivalent Ca(1), two equivalent Mg(2), and four equivalent Mg(1) atoms to form a mixture of corner, edge, and face-sharing MgCa6Mg6 cuboctahedra. is represented by the CIF card [CIF]
data_CaMg2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.320
_cell_length_b   6.320
_cell_length_c   6.320
_cell_angle_alpha   58.046
_cell_angle_beta   58.046
_cell_angle_gamma   58.046
_symmetry_Int_Tables_number   1
_cell_volume   170.501
_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  0.876  0.876  0.876  1.0
  Ca  Ca1  1  0.124  0.124  0.124  1.0
  Mg  Mg2  1  0.500  0.000  0.500  1.0
  Mg  Mg3  1  0.000  0.500  0.500  1.0
  Mg  Mg4  1  0.500  0.500  0.500  1.0
  Mg  Mg5  1  0.500  0.500  0.000  1.0
[/CIF]
.