The material described by CaMg7 crystallizes in the hexagonal P-6m2 space group. Ca(1) is bonded to six Mg(1,1) and six Mg(2,2) atoms to form CaMg12 cuboctahedra that share corners with six equivalent Ca(1)Mg12 cuboctahedra; corners with twelve Mg(1,1)Ca2Mg10 cuboctahedra; edges with six Mg(1,1)Ca2Mg10 cuboctahedra; edges with twelve Mg(2,2)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Mg12 cuboctahedra; faces with six Mg(1,1)Ca2Mg10 cuboctahedra; faces with six Mg(2,2)Ca2Mg10 cuboctahedra; and faces with six equivalent Mg(3)Mg12 cuboctahedra. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Ca(1), two equivalent Mg(3), four equivalent Mg(1), and four equivalent Mg(2) atoms to form distorted MgCa2Mg10 cuboctahedra that share corners with four equivalent Ca(1)Mg12 cuboctahedra; corners with fourteen Mg(1,1)Ca2Mg10 cuboctahedra; edges with two equivalent Ca(1)Mg12 cuboctahedra; edges with four equivalent Mg(1)Ca2Mg10 cuboctahedra; edges with four equivalent Mg(3)Mg12 cuboctahedra; edges with eight equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(1,1)Ca2Mg10 cuboctahedra; and faces with ten Mg(2,2)Ca2Mg10 cuboctahedra. In the second Mg site, Mg(1) is bonded to two equivalent Ca(1); two equivalent Mg(3); four Mg(1,1); and four Mg(2,2) atoms to form distorted MgCa2Mg10 cuboctahedra that share corners with four equivalent Ca(1)Mg12 cuboctahedra; corners with fourteen Mg(1,1)Ca2Mg10 cuboctahedra; edges with two equivalent Ca(1)Mg12 cuboctahedra; edges with four Mg(1,1)Ca2Mg10 cuboctahedra; edges with four equivalent Mg(3)Mg12 cuboctahedra; edges with eight Mg(2,2)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(1,1)Ca2Mg10 cuboctahedra; and faces with ten Mg(2,2)Ca2Mg10 cuboctahedra. In the third Mg site, Mg(2) is bonded to two equivalent Ca(1); two equivalent Mg(3); four Mg(1,1); and four Mg(2,2) atoms to form distorted MgCa2Mg10 cuboctahedra that share corners with four equivalent Mg(3)Mg12 cuboctahedra; corners with fourteen Mg(2,2)Ca2Mg10 cuboctahedra; edges with two equivalent Mg(3)Mg12 cuboctahedra; edges with four equivalent Ca(1)Mg12 cuboctahedra; edges with four Mg(2,2)Ca2Mg10 cuboctahedra; edges with eight Mg(1,1)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(2,2)Ca2Mg10 cuboctahedra; and faces with ten Mg(1,1)Ca2Mg10 cuboctahedra. In the fourth Mg site, Mg(2) is bonded to two equivalent Ca(1), two equivalent Mg(3), four equivalent Mg(1), and four equivalent Mg(2) atoms to form distorted MgCa2Mg10 cuboctahedra that share corners with four equivalent Mg(3)Mg12 cuboctahedra; corners with fourteen Mg(2,2)Ca2Mg10 cuboctahedra; edges with two equivalent Mg(3)Mg12 cuboctahedra; edges with four equivalent Ca(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Ca2Mg10 cuboctahedra; edges with eight equivalent Mg(1)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(2,2)Ca2Mg10 cuboctahedra; and faces with ten Mg(1,1)Ca2Mg10 cuboctahedra. In the fifth Mg site, Mg(3) is bonded to six Mg(1,1) and six Mg(2,2) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(3)Mg12 cuboctahedra; corners with twelve Mg(2,2)Ca2Mg10 cuboctahedra; edges with six Mg(2,2)Ca2Mg10 cuboctahedra; edges with twelve Mg(1,1)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six equivalent Ca(1)Mg12 cuboctahedra; faces with six Mg(1,1)Ca2Mg10 cuboctahedra; and faces with six Mg(2,2)Ca2Mg10 cuboctahedra. is represented by the CIF file [CIF]
data_CaMg7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.648
_cell_length_b   6.648
_cell_length_c   5.258
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   201.216
_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  0.000  0.500  1.0
  Mg  Mg1  1  0.005  0.502  0.500  1.0
  Mg  Mg2  1  0.498  0.502  0.500  1.0
  Mg  Mg3  1  0.498  0.995  0.500  1.0
  Mg  Mg4  1  0.170  0.340  0.000  1.0
  Mg  Mg5  1  0.170  0.830  0.000  1.0
  Mg  Mg6  1  0.660  0.830  0.000  1.0
  Mg  Mg7  1  0.667  0.333  0.000  1.0
[/CIF]
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The material described by CaMg7 crystallizes in the hexagonal P-6m2 space group. Ca(1) is bonded to six Mg(1,1) and six Mg(2,2) atoms to form CaMg12 cuboctahedra that share corners with six equivalent Ca(1)Mg12 cuboctahedra; corners with twelve Mg(1,1)Ca2Mg10 cuboctahedra; edges with six Mg(1,1)Ca2Mg10 cuboctahedra; edges with twelve Mg(2,2)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Mg12 cuboctahedra; faces with six Mg(1,1)Ca2Mg10 cuboctahedra; faces with six Mg(2,2)Ca2Mg10 cuboctahedra; and faces with six equivalent Mg(3)Mg12 cuboctahedra. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Ca(1), two equivalent Mg(3), four equivalent Mg(1), and four equivalent Mg(2) atoms to form distorted MgCa2Mg10 cuboctahedra that share corners with four equivalent Ca(1)Mg12 cuboctahedra; corners with fourteen Mg(1,1)Ca2Mg10 cuboctahedra; edges with two equivalent Ca(1)Mg12 cuboctahedra; edges with four equivalent Mg(1)Ca2Mg10 cuboctahedra; edges with four equivalent Mg(3)Mg12 cuboctahedra; edges with eight equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(1,1)Ca2Mg10 cuboctahedra; and faces with ten Mg(2,2)Ca2Mg10 cuboctahedra. In the second Mg site, Mg(1) is bonded to two equivalent Ca(1); two equivalent Mg(3); four Mg(1,1); and four Mg(2,2) atoms to form distorted MgCa2Mg10 cuboctahedra that share corners with four equivalent Ca(1)Mg12 cuboctahedra; corners with fourteen Mg(1,1)Ca2Mg10 cuboctahedra; edges with two equivalent Ca(1)Mg12 cuboctahedra; edges with four Mg(1,1)Ca2Mg10 cuboctahedra; edges with four equivalent Mg(3)Mg12 cuboctahedra; edges with eight Mg(2,2)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(1,1)Ca2Mg10 cuboctahedra; and faces with ten Mg(2,2)Ca2Mg10 cuboctahedra. In the third Mg site, Mg(2) is bonded to two equivalent Ca(1); two equivalent Mg(3); four Mg(1,1); and four Mg(2,2) atoms to form distorted MgCa2Mg10 cuboctahedra that share corners with four equivalent Mg(3)Mg12 cuboctahedra; corners with fourteen Mg(2,2)Ca2Mg10 cuboctahedra; edges with two equivalent Mg(3)Mg12 cuboctahedra; edges with four equivalent Ca(1)Mg12 cuboctahedra; edges with four Mg(2,2)Ca2Mg10 cuboctahedra; edges with eight Mg(1,1)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(2,2)Ca2Mg10 cuboctahedra; and faces with ten Mg(1,1)Ca2Mg10 cuboctahedra. In the fourth Mg site, Mg(2) is bonded to two equivalent Ca(1), two equivalent Mg(3), four equivalent Mg(1), and four equivalent Mg(2) atoms to form distorted MgCa2Mg10 cuboctahedra that share corners with four equivalent Mg(3)Mg12 cuboctahedra; corners with fourteen Mg(2,2)Ca2Mg10 cuboctahedra; edges with two equivalent Mg(3)Mg12 cuboctahedra; edges with four equivalent Ca(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Ca2Mg10 cuboctahedra; edges with eight equivalent Mg(1)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(2,2)Ca2Mg10 cuboctahedra; and faces with ten Mg(1,1)Ca2Mg10 cuboctahedra. In the fifth Mg site, Mg(3) is bonded to six Mg(1,1) and six Mg(2,2) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(3)Mg12 cuboctahedra; corners with twelve Mg(2,2)Ca2Mg10 cuboctahedra; edges with six Mg(2,2)Ca2Mg10 cuboctahedra; edges with twelve Mg(1,1)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six equivalent Ca(1)Mg12 cuboctahedra; faces with six Mg(1,1)Ca2Mg10 cuboctahedra; and faces with six Mg(2,2)Ca2Mg10 cuboctahedra. is represented by the CIF file [CIF]
data_CaMg7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.648
_cell_length_b   6.648
_cell_length_c   5.258
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   201.216
_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  0.000  0.500  1.0
  Mg  Mg1  1  0.005  0.502  0.500  1.0
  Mg  Mg2  1  0.498  0.502  0.500  1.0
  Mg  Mg3  1  0.498  0.995  0.500  1.0
  Mg  Mg4  1  0.170  0.340  0.000  1.0
  Mg  Mg5  1  0.170  0.830  0.000  1.0
  Mg  Mg6  1  0.660  0.830  0.000  1.0
  Mg  Mg7  1  0.667  0.333  0.000  1.0
[/CIF]
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