The material structure described by Ca2Mg crystallizes in the monoclinic Cm space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent Ca(1), two equivalent Ca(2), two equivalent Ca(3), three equivalent Ca(4), one Mg(2), and two equivalent Mg(1) atoms to form distorted CaCa9Mg3 cuboctahedra that share corners with six equivalent Ca(2)Ca7Mg5 cuboctahedra, corners with six equivalent Ca(1)Ca9Mg3 cuboctahedra, edges with two equivalent Ca(4)Ca8Mg4 cuboctahedra, edges with three equivalent Ca(2)Ca7Mg5 cuboctahedra, faces with two equivalent Ca(1)Ca9Mg3 cuboctahedra, faces with three equivalent Ca(2)Ca7Mg5 cuboctahedra, and faces with five equivalent Ca(4)Ca8Mg4 cuboctahedra. In the second Ca site, Ca(2) is bonded to one Ca(4), two equivalent Ca(1), two equivalent Ca(2), two equivalent Ca(3), two equivalent Mg(2), and three equivalent Mg(1) atoms to form distorted CaCa7Mg5 cuboctahedra that share corners with six equivalent Ca(2)Ca7Mg5 cuboctahedra, corners with six equivalent Ca(1)Ca9Mg3 cuboctahedra, edges with three equivalent Ca(1)Ca9Mg3 cuboctahedra, edges with four equivalent Ca(4)Ca8Mg4 cuboctahedra, faces with two equivalent Ca(2)Ca7Mg5 cuboctahedra, faces with three equivalent Ca(1)Ca9Mg3 cuboctahedra, and faces with four equivalent Ca(4)Ca8Mg4 cuboctahedra. In the third Ca site, Ca(3) is bonded in a 3-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), two equivalent Ca(4), one Mg(1), and two equivalent Mg(2) atoms. In the fourth Ca site, Ca(4) is bonded to one Ca(2), two equivalent Ca(3), two equivalent Ca(4), three equivalent Ca(1), two equivalent Mg(1), and two equivalent Mg(2) atoms to form distorted CaCa8Mg4 cuboctahedra that share corners with six equivalent Ca(4)Ca8Mg4 cuboctahedra, edges with two equivalent Ca(1)Ca9Mg3 cuboctahedra, edges with four equivalent Ca(2)Ca7Mg5 cuboctahedra, faces with two equivalent Ca(4)Ca8Mg4 cuboctahedra, faces with four equivalent Ca(2)Ca7Mg5 cuboctahedra, and faces with five equivalent Ca(1)Ca9Mg3 cuboctahedra. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to one Ca(3), two equivalent Ca(1), two equivalent Ca(4), and three equivalent Ca(2) atoms. In the second Mg site, Mg(2) is bonded in a 7-coordinate geometry to one Ca(1), two equivalent Ca(2), two equivalent Ca(3), and two equivalent Ca(4) atoms. is represented by the CIF file [CIF]
data_Ca2Mg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.219
_cell_length_b   7.219
_cell_length_c   8.515
_cell_angle_alpha   76.812
_cell_angle_beta   76.812
_cell_angle_gamma   29.742
_symmetry_Int_Tables_number   1
_cell_volume   213.943
_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  0.007  0.007  0.009  1.0
  Ca  Ca1  1  0.335  0.335  0.345  1.0
  Ca  Ca2  1  0.653  0.653  0.654  1.0
  Ca  Ca3  1  0.280  0.280  0.939  1.0
  Mg  Mg4  1  0.613  0.613  0.276  1.0
  Mg  Mg5  1  0.943  0.943  0.611  1.0
[/CIF]
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The material structure described by Ca2Mg crystallizes in the monoclinic Cm space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent Ca(1), two equivalent Ca(2), two equivalent Ca(3), three equivalent Ca(4), one Mg(2), and two equivalent Mg(1) atoms to form distorted CaCa9Mg3 cuboctahedra that share corners with six equivalent Ca(2)Ca7Mg5 cuboctahedra, corners with six equivalent Ca(1)Ca9Mg3 cuboctahedra, edges with two equivalent Ca(4)Ca8Mg4 cuboctahedra, edges with three equivalent Ca(2)Ca7Mg5 cuboctahedra, faces with two equivalent Ca(1)Ca9Mg3 cuboctahedra, faces with three equivalent Ca(2)Ca7Mg5 cuboctahedra, and faces with five equivalent Ca(4)Ca8Mg4 cuboctahedra. In the second Ca site, Ca(2) is bonded to one Ca(4), two equivalent Ca(1), two equivalent Ca(2), two equivalent Ca(3), two equivalent Mg(2), and three equivalent Mg(1) atoms to form distorted CaCa7Mg5 cuboctahedra that share corners with six equivalent Ca(2)Ca7Mg5 cuboctahedra, corners with six equivalent Ca(1)Ca9Mg3 cuboctahedra, edges with three equivalent Ca(1)Ca9Mg3 cuboctahedra, edges with four equivalent Ca(4)Ca8Mg4 cuboctahedra, faces with two equivalent Ca(2)Ca7Mg5 cuboctahedra, faces with three equivalent Ca(1)Ca9Mg3 cuboctahedra, and faces with four equivalent Ca(4)Ca8Mg4 cuboctahedra. In the third Ca site, Ca(3) is bonded in a 3-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), two equivalent Ca(4), one Mg(1), and two equivalent Mg(2) atoms. In the fourth Ca site, Ca(4) is bonded to one Ca(2), two equivalent Ca(3), two equivalent Ca(4), three equivalent Ca(1), two equivalent Mg(1), and two equivalent Mg(2) atoms to form distorted CaCa8Mg4 cuboctahedra that share corners with six equivalent Ca(4)Ca8Mg4 cuboctahedra, edges with two equivalent Ca(1)Ca9Mg3 cuboctahedra, edges with four equivalent Ca(2)Ca7Mg5 cuboctahedra, faces with two equivalent Ca(4)Ca8Mg4 cuboctahedra, faces with four equivalent Ca(2)Ca7Mg5 cuboctahedra, and faces with five equivalent Ca(1)Ca9Mg3 cuboctahedra. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to one Ca(3), two equivalent Ca(1), two equivalent Ca(4), and three equivalent Ca(2) atoms. In the second Mg site, Mg(2) is bonded in a 7-coordinate geometry to one Ca(1), two equivalent Ca(2), two equivalent Ca(3), and two equivalent Ca(4) atoms. is represented by the CIF file [CIF]
data_Ca2Mg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.219
_cell_length_b   7.219
_cell_length_c   8.515
_cell_angle_alpha   76.812
_cell_angle_beta   76.812
_cell_angle_gamma   29.742
_symmetry_Int_Tables_number   1
_cell_volume   213.943
_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  0.007  0.007  0.009  1.0
  Ca  Ca1  1  0.335  0.335  0.345  1.0
  Ca  Ca2  1  0.653  0.653  0.654  1.0
  Ca  Ca3  1  0.280  0.280  0.939  1.0
  Mg  Mg4  1  0.613  0.613  0.276  1.0
  Mg  Mg5  1  0.943  0.943  0.611  1.0
[/CIF]
.