The compound described by CeMg2 crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), four equivalent Mg(4), and two equivalent Ce(1) atoms to form MgCe2Mg10 cuboctahedra that share corners with six equivalent Mg(1)Ce2Mg10 cuboctahedra, corners with six equivalent Mg(2)Ce4Mg8 cuboctahedra, corners with six equivalent Mg(3)Ce6Mg6 cuboctahedra, edges with three equivalent Mg(2)Ce4Mg8 cuboctahedra, edges with three equivalent Mg(3)Ce6Mg6 cuboctahedra, edges with four equivalent Mg(4)Ce4Mg8 cuboctahedra, edges with eight equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(2)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(3)Ce6Mg6 cuboctahedra, faces with two equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(1)Ce2Mg10 cuboctahedra, faces with four equivalent Mg(4)Ce4Mg8 cuboctahedra, and faces with six equivalent Ce(1)Ce4Mg8 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and four equivalent Ce(2) atoms to form MgCe4Mg8 cuboctahedra that share corners with six equivalent Mg(1)Ce2Mg10 cuboctahedra, corners with six equivalent Mg(2)Ce4Mg8 cuboctahedra, corners with six equivalent Mg(3)Ce6Mg6 cuboctahedra, edges with three equivalent Mg(1)Ce2Mg10 cuboctahedra, edges with three equivalent Mg(3)Ce6Mg6 cuboctahedra, edges with four equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with eight equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(1)Ce2Mg10 cuboctahedra, faces with two equivalent Mg(3)Ce6Mg6 cuboctahedra, faces with two equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(2)Ce4Mg8 cuboctahedra, faces with four equivalent Ce(2)Ce4Mg8 cuboctahedra, and faces with six equivalent Mg(4)Ce4Mg8 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Ce(2), and four equivalent Ce(1) atoms to form MgCe6Mg6 cuboctahedra that share corners with six equivalent Mg(1)Ce2Mg10 cuboctahedra, corners with six equivalent Mg(2)Ce4Mg8 cuboctahedra, corners with six equivalent Mg(3)Ce6Mg6 cuboctahedra, edges with three equivalent Mg(1)Ce2Mg10 cuboctahedra, edges with three equivalent Mg(2)Ce4Mg8 cuboctahedra, edges with four equivalent Ce(1)Ce4Mg8 cuboctahedra, edges with eight equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(1)Ce2Mg10 cuboctahedra, faces with two equivalent Mg(2)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(3)Ce6Mg6 cuboctahedra, faces with four equivalent Ce(1)Ce4Mg8 cuboctahedra, and faces with six equivalent Ce(2)Ce4Mg8 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(2), two equivalent Mg(4), four equivalent Mg(1), two equivalent Ce(1), and two equivalent Ce(2) atoms to form MgCe4Mg8 cuboctahedra that share corners with six equivalent Mg(4)Ce4Mg8 cuboctahedra, corners with six equivalent Ce(1)Ce4Mg8 cuboctahedra, corners with six equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with three equivalent Ce(1)Ce4Mg8 cuboctahedra, edges with three equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with four equivalent Mg(1)Ce2Mg10 cuboctahedra, edges with eight equivalent Mg(3)Ce6Mg6 cuboctahedra, faces with two equivalent Mg(3)Ce6Mg6 cuboctahedra, faces with two equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with two equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(1)Ce2Mg10 cuboctahedra, faces with four equivalent Mg(4)Ce4Mg8 cuboctahedra, and faces with six equivalent Mg(2)Ce4Mg8 cuboctahedra. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to two equivalent Mg(1), two equivalent Mg(4), four equivalent Mg(3), two equivalent Ce(1), and two equivalent Ce(2) atoms to form CeCe4Mg8 cuboctahedra that share corners with six equivalent Mg(4)Ce4Mg8 cuboctahedra, corners with six equivalent Ce(1)Ce4Mg8 cuboctahedra, corners with six equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with three equivalent Mg(4)Ce4Mg8 cuboctahedra, edges with three equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with four equivalent Mg(3)Ce6Mg6 cuboctahedra, edges with eight equivalent Mg(2)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(2)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with two equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(3)Ce6Mg6 cuboctahedra, faces with four equivalent Ce(1)Ce4Mg8 cuboctahedra, and faces with six equivalent Mg(1)Ce2Mg10 cuboctahedra. In the second Ce site, Ce(2) is bonded to two equivalent Mg(3), two equivalent Mg(4), four equivalent Mg(2), two equivalent Ce(1), and two equivalent Ce(2) atoms to form CeCe4Mg8 cuboctahedra that share corners with six equivalent Mg(4)Ce4Mg8 cuboctahedra, corners with six equivalent Ce(1)Ce4Mg8 cuboctahedra, corners with six equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with three equivalent Mg(4)Ce4Mg8 cuboctahedra, edges with three equivalent Ce(1)Ce4Mg8 cuboctahedra, edges with four equivalent Mg(2)Ce4Mg8 cuboctahedra, edges with eight equivalent Mg(1)Ce2Mg10 cuboctahedra, faces with two equivalent Mg(1)Ce2Mg10 cuboctahedra, faces with two equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with two equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(2)Ce4Mg8 cuboctahedra, faces with four equivalent Ce(2)Ce4Mg8 cuboctahedra, and faces with six equivalent Mg(3)Ce6Mg6 cuboctahedra. is represented by the CIF card [CIF]
data_CeMg2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.623
_cell_length_b   8.623
_cell_length_c   5.656
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   158.988
_symmetry_Int_Tables_number   1
_cell_volume   150.803
_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
  Ce  Ce0  1  0.124  0.876  0.500  1.0
  Ce  Ce1  1  0.766  0.234  0.500  1.0
  Mg  Mg2  1  0.998  0.002  0.000  1.0
  Mg  Mg3  1  0.333  0.667  0.000  1.0
  Mg  Mg4  1  0.668  0.332  0.000  1.0
  Mg  Mg5  1  0.445  0.555  0.500  1.0
[/CIF]
.
The compound described by CeMg2 crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), four equivalent Mg(4), and two equivalent Ce(1) atoms to form MgCe2Mg10 cuboctahedra that share corners with six equivalent Mg(1)Ce2Mg10 cuboctahedra, corners with six equivalent Mg(2)Ce4Mg8 cuboctahedra, corners with six equivalent Mg(3)Ce6Mg6 cuboctahedra, edges with three equivalent Mg(2)Ce4Mg8 cuboctahedra, edges with three equivalent Mg(3)Ce6Mg6 cuboctahedra, edges with four equivalent Mg(4)Ce4Mg8 cuboctahedra, edges with eight equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(2)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(3)Ce6Mg6 cuboctahedra, faces with two equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(1)Ce2Mg10 cuboctahedra, faces with four equivalent Mg(4)Ce4Mg8 cuboctahedra, and faces with six equivalent Ce(1)Ce4Mg8 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and four equivalent Ce(2) atoms to form MgCe4Mg8 cuboctahedra that share corners with six equivalent Mg(1)Ce2Mg10 cuboctahedra, corners with six equivalent Mg(2)Ce4Mg8 cuboctahedra, corners with six equivalent Mg(3)Ce6Mg6 cuboctahedra, edges with three equivalent Mg(1)Ce2Mg10 cuboctahedra, edges with three equivalent Mg(3)Ce6Mg6 cuboctahedra, edges with four equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with eight equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(1)Ce2Mg10 cuboctahedra, faces with two equivalent Mg(3)Ce6Mg6 cuboctahedra, faces with two equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(2)Ce4Mg8 cuboctahedra, faces with four equivalent Ce(2)Ce4Mg8 cuboctahedra, and faces with six equivalent Mg(4)Ce4Mg8 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Ce(2), and four equivalent Ce(1) atoms to form MgCe6Mg6 cuboctahedra that share corners with six equivalent Mg(1)Ce2Mg10 cuboctahedra, corners with six equivalent Mg(2)Ce4Mg8 cuboctahedra, corners with six equivalent Mg(3)Ce6Mg6 cuboctahedra, edges with three equivalent Mg(1)Ce2Mg10 cuboctahedra, edges with three equivalent Mg(2)Ce4Mg8 cuboctahedra, edges with four equivalent Ce(1)Ce4Mg8 cuboctahedra, edges with eight equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(1)Ce2Mg10 cuboctahedra, faces with two equivalent Mg(2)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(3)Ce6Mg6 cuboctahedra, faces with four equivalent Ce(1)Ce4Mg8 cuboctahedra, and faces with six equivalent Ce(2)Ce4Mg8 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(2), two equivalent Mg(4), four equivalent Mg(1), two equivalent Ce(1), and two equivalent Ce(2) atoms to form MgCe4Mg8 cuboctahedra that share corners with six equivalent Mg(4)Ce4Mg8 cuboctahedra, corners with six equivalent Ce(1)Ce4Mg8 cuboctahedra, corners with six equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with three equivalent Ce(1)Ce4Mg8 cuboctahedra, edges with three equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with four equivalent Mg(1)Ce2Mg10 cuboctahedra, edges with eight equivalent Mg(3)Ce6Mg6 cuboctahedra, faces with two equivalent Mg(3)Ce6Mg6 cuboctahedra, faces with two equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with two equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(1)Ce2Mg10 cuboctahedra, faces with four equivalent Mg(4)Ce4Mg8 cuboctahedra, and faces with six equivalent Mg(2)Ce4Mg8 cuboctahedra. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to two equivalent Mg(1), two equivalent Mg(4), four equivalent Mg(3), two equivalent Ce(1), and two equivalent Ce(2) atoms to form CeCe4Mg8 cuboctahedra that share corners with six equivalent Mg(4)Ce4Mg8 cuboctahedra, corners with six equivalent Ce(1)Ce4Mg8 cuboctahedra, corners with six equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with three equivalent Mg(4)Ce4Mg8 cuboctahedra, edges with three equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with four equivalent Mg(3)Ce6Mg6 cuboctahedra, edges with eight equivalent Mg(2)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(2)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with two equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(3)Ce6Mg6 cuboctahedra, faces with four equivalent Ce(1)Ce4Mg8 cuboctahedra, and faces with six equivalent Mg(1)Ce2Mg10 cuboctahedra. In the second Ce site, Ce(2) is bonded to two equivalent Mg(3), two equivalent Mg(4), four equivalent Mg(2), two equivalent Ce(1), and two equivalent Ce(2) atoms to form CeCe4Mg8 cuboctahedra that share corners with six equivalent Mg(4)Ce4Mg8 cuboctahedra, corners with six equivalent Ce(1)Ce4Mg8 cuboctahedra, corners with six equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with three equivalent Mg(4)Ce4Mg8 cuboctahedra, edges with three equivalent Ce(1)Ce4Mg8 cuboctahedra, edges with four equivalent Mg(2)Ce4Mg8 cuboctahedra, edges with eight equivalent Mg(1)Ce2Mg10 cuboctahedra, faces with two equivalent Mg(1)Ce2Mg10 cuboctahedra, faces with two equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with two equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(2)Ce4Mg8 cuboctahedra, faces with four equivalent Ce(2)Ce4Mg8 cuboctahedra, and faces with six equivalent Mg(3)Ce6Mg6 cuboctahedra. is represented by the CIF card [CIF]
data_CeMg2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.623
_cell_length_b   8.623
_cell_length_c   5.656
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   158.988
_symmetry_Int_Tables_number   1
_cell_volume   150.803
_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
  Ce  Ce0  1  0.124  0.876  0.500  1.0
  Ce  Ce1  1  0.766  0.234  0.500  1.0
  Mg  Mg2  1  0.998  0.002  0.000  1.0
  Mg  Mg3  1  0.333  0.667  0.000  1.0
  Mg  Mg4  1  0.668  0.332  0.000  1.0
  Mg  Mg5  1  0.445  0.555  0.500  1.0
[/CIF]
.