The crystal structure described by MgCa crystallizes in the orthorhombic Amm2 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to two equivalent Ca(3), two equivalent Mg(1), and four equivalent Mg(2) atoms. In the second Ca site, Ca(2) is bonded in a 4-coordinate geometry to four equivalent Ca(3), two equivalent Mg(1), and two equivalent Mg(3) atoms. In the third Ca site, Ca(3) is bonded to two equivalent Ca(1), two equivalent Ca(3), four equivalent Ca(2), two equivalent Mg(2), and two equivalent Mg(3) atoms to form a mixture of distorted face and corner-sharing CaCa8Mg4 cuboctahedra. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), two equivalent Mg(2), and four equivalent Mg(3) atoms. In the second Mg site, Mg(2) is bonded in a 10-coordinate geometry to two equivalent Ca(3), four equivalent Ca(1), two equivalent Mg(1), and two equivalent Mg(3) atoms. In the third Mg site, Mg(3) is bonded in a 10-coordinate geometry to two equivalent Ca(2), two equivalent Ca(3), two equivalent Mg(2), and four equivalent Mg(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaMg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.894
_cell_length_b   5.588
_cell_length_c   9.098
_cell_angle_alpha   90.000
_cell_angle_beta   102.358
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   193.398
_cell_formula_units_Z   3
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  0.982  0.000  0.964  1.0
  Ca  Ca1  1  0.678  0.000  0.355  1.0
  Ca  Ca2  1  0.113  0.500  0.227  1.0
  Mg  Mg3  1  0.331  0.000  0.661  1.0
  Mg  Mg4  1  0.437  0.500  0.873  1.0
  Mg  Mg5  1  0.793  0.500  0.586  1.0
[/CIF]
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The crystal structure described by MgCa crystallizes in the orthorhombic Amm2 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to two equivalent Ca(3), two equivalent Mg(1), and four equivalent Mg(2) atoms. In the second Ca site, Ca(2) is bonded in a 4-coordinate geometry to four equivalent Ca(3), two equivalent Mg(1), and two equivalent Mg(3) atoms. In the third Ca site, Ca(3) is bonded to two equivalent Ca(1), two equivalent Ca(3), four equivalent Ca(2), two equivalent Mg(2), and two equivalent Mg(3) atoms to form a mixture of distorted face and corner-sharing CaCa8Mg4 cuboctahedra. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), two equivalent Mg(2), and four equivalent Mg(3) atoms. In the second Mg site, Mg(2) is bonded in a 10-coordinate geometry to two equivalent Ca(3), four equivalent Ca(1), two equivalent Mg(1), and two equivalent Mg(3) atoms. In the third Mg site, Mg(3) is bonded in a 10-coordinate geometry to two equivalent Ca(2), two equivalent Ca(3), two equivalent Mg(2), and four equivalent Mg(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaMg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.894
_cell_length_b   5.588
_cell_length_c   9.098
_cell_angle_alpha   90.000
_cell_angle_beta   102.358
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   193.398
_cell_formula_units_Z   3
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  0.982  0.000  0.964  1.0
  Ca  Ca1  1  0.678  0.000  0.355  1.0
  Ca  Ca2  1  0.113  0.500  0.227  1.0
  Mg  Mg3  1  0.331  0.000  0.661  1.0
  Mg  Mg4  1  0.437  0.500  0.873  1.0
  Mg  Mg5  1  0.793  0.500  0.586  1.0
[/CIF]
.