The material described by CeMg2 is beta-derived structured and crystallizes in the monoclinic Cm 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), three equivalent Mg(4), one Ce(2), and two equivalent Ce(1) atoms to form distorted MgCe3Mg9 cuboctahedra that share corners with six equivalent Mg(1)Ce3Mg9 cuboctahedra, corners with six equivalent Mg(3)Ce4Mg8 cuboctahedra, corners with six equivalent Mg(2)Ce5Mg7 cuboctahedra, edges with two equivalent Mg(4)Ce4Mg8 cuboctahedra, edges with three equivalent Mg(3)Ce4Mg8 cuboctahedra, edges with three equivalent Mg(2)Ce5Mg7 cuboctahedra, edges with four equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with six equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(1)Ce3Mg9 cuboctahedra, faces with three equivalent Mg(3)Ce4Mg8 cuboctahedra, faces with three equivalent Mg(2)Ce5Mg7 cuboctahedra, faces with three equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with four equivalent Ce(2)Ce4Mg8 cuboctahedra, and faces with five equivalent Mg(4)Ce4Mg8 cuboctahedra. In the second Mg site, Mg(2) is bonded to one Mg(4), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Ce(2), and three equivalent Ce(1) atoms to form MgCe5Mg7 cuboctahedra that share corners with six equivalent Mg(1)Ce3Mg9 cuboctahedra, corners with six equivalent Mg(3)Ce4Mg8 cuboctahedra, corners with six equivalent Mg(2)Ce5Mg7 cuboctahedra, edges with two equivalent Ce(1)Ce4Mg8 cuboctahedra, edges with three equivalent Mg(1)Ce3Mg9 cuboctahedra, edges with three equivalent Mg(3)Ce4Mg8 cuboctahedra, edges with four equivalent Mg(4)Ce4Mg8 cuboctahedra, edges with six equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(2)Ce5Mg7 cuboctahedra, faces with three equivalent Mg(1)Ce3Mg9 cuboctahedra, faces with three equivalent Mg(3)Ce4Mg8 cuboctahedra, faces with three equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(4)Ce4Mg8 cuboctahedra, and faces with five equivalent Ce(1)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 Mg(4), one Ce(1), and three equivalent Ce(2) atoms to form MgCe4Mg8 cuboctahedra that share corners with six equivalent Mg(1)Ce3Mg9 cuboctahedra, corners with six equivalent Mg(3)Ce4Mg8 cuboctahedra, corners with six equivalent Mg(2)Ce5Mg7 cuboctahedra, edges with two equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with three equivalent Mg(1)Ce3Mg9 cuboctahedra, edges with three equivalent Mg(2)Ce5Mg7 cuboctahedra, edges with four equivalent Ce(1)Ce4Mg8 cuboctahedra, edges with six equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(3)Ce4Mg8 cuboctahedra, faces with three equivalent Mg(1)Ce3Mg9 cuboctahedra, faces with three equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with three equivalent Mg(2)Ce5Mg7 cuboctahedra, faces with four equivalent Ce(1)Ce4Mg8 cuboctahedra, and faces with five equivalent Ce(2)Ce4Mg8 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to one Mg(2), two equivalent Mg(3), two equivalent Mg(4), three equivalent Mg(1), two equivalent Ce(1), and two equivalent Ce(2) atoms to form distorted 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 two equivalent Mg(1)Ce3Mg9 cuboctahedra, edges with three equivalent Ce(1)Ce4Mg8 cuboctahedra, edges with three equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with four equivalent Mg(2)Ce5Mg7 cuboctahedra, edges with six equivalent Mg(3)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with three equivalent Mg(3)Ce4Mg8 cuboctahedra, faces with three equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with three equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(2)Ce5Mg7 cuboctahedra, and faces with five equivalent Mg(1)Ce3Mg9 cuboctahedra. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Mg(3), two equivalent Mg(1), two equivalent Mg(4), three 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 two equivalent Mg(2)Ce5Mg7 cuboctahedra, edges with three equivalent Mg(4)Ce4Mg8 cuboctahedra, edges with three equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with four equivalent Mg(3)Ce4Mg8 cuboctahedra, edges with six equivalent Mg(1)Ce3Mg9 cuboctahedra, faces with two equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with three equivalent Mg(1)Ce3Mg9 cuboctahedra, faces with three equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with three equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(3)Ce4Mg8 cuboctahedra, and faces with five equivalent Mg(2)Ce5Mg7 cuboctahedra. In the second Ce site, Ce(2) is bonded to one Mg(1), two equivalent Mg(2), two equivalent Mg(4), three 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 two equivalent Mg(3)Ce4Mg8 cuboctahedra, edges with three equivalent Mg(4)Ce4Mg8 cuboctahedra, edges with three equivalent Ce(1)Ce4Mg8 cuboctahedra, edges with four equivalent Mg(1)Ce3Mg9 cuboctahedra, edges with six equivalent Mg(2)Ce5Mg7 cuboctahedra, faces with two equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with three equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with three equivalent Mg(2)Ce5Mg7 cuboctahedra, faces with three equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(1)Ce3Mg9 cuboctahedra, and faces with five equivalent Mg(3)Ce4Mg8 cuboctahedra. is represented by the CIF card [CIF]
data_CeMg2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.579
_cell_length_b   6.579
_cell_length_c   7.849
_cell_angle_alpha   72.701
_cell_angle_beta   72.701
_cell_angle_gamma   28.024
_symmetry_Int_Tables_number   1
_cell_volume   151.945
_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  0.596  0.596  0.309  1.0
  Ce  Ce1  1  0.960  0.960  0.578  1.0
  Mg  Mg2  1  0.996  0.996  0.996  1.0
  Mg  Mg3  1  0.329  0.329  0.322  1.0
  Mg  Mg4  1  0.676  0.676  0.680  1.0
  Mg  Mg5  1  0.277  0.277  0.949  1.0
[/CIF]
.
The material described by CeMg2 is beta-derived structured and crystallizes in the monoclinic Cm 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), three equivalent Mg(4), one Ce(2), and two equivalent Ce(1) atoms to form distorted MgCe3Mg9 cuboctahedra that share corners with six equivalent Mg(1)Ce3Mg9 cuboctahedra, corners with six equivalent Mg(3)Ce4Mg8 cuboctahedra, corners with six equivalent Mg(2)Ce5Mg7 cuboctahedra, edges with two equivalent Mg(4)Ce4Mg8 cuboctahedra, edges with three equivalent Mg(3)Ce4Mg8 cuboctahedra, edges with three equivalent Mg(2)Ce5Mg7 cuboctahedra, edges with four equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with six equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(1)Ce3Mg9 cuboctahedra, faces with three equivalent Mg(3)Ce4Mg8 cuboctahedra, faces with three equivalent Mg(2)Ce5Mg7 cuboctahedra, faces with three equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with four equivalent Ce(2)Ce4Mg8 cuboctahedra, and faces with five equivalent Mg(4)Ce4Mg8 cuboctahedra. In the second Mg site, Mg(2) is bonded to one Mg(4), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Ce(2), and three equivalent Ce(1) atoms to form MgCe5Mg7 cuboctahedra that share corners with six equivalent Mg(1)Ce3Mg9 cuboctahedra, corners with six equivalent Mg(3)Ce4Mg8 cuboctahedra, corners with six equivalent Mg(2)Ce5Mg7 cuboctahedra, edges with two equivalent Ce(1)Ce4Mg8 cuboctahedra, edges with three equivalent Mg(1)Ce3Mg9 cuboctahedra, edges with three equivalent Mg(3)Ce4Mg8 cuboctahedra, edges with four equivalent Mg(4)Ce4Mg8 cuboctahedra, edges with six equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(2)Ce5Mg7 cuboctahedra, faces with three equivalent Mg(1)Ce3Mg9 cuboctahedra, faces with three equivalent Mg(3)Ce4Mg8 cuboctahedra, faces with three equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(4)Ce4Mg8 cuboctahedra, and faces with five equivalent Ce(1)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 Mg(4), one Ce(1), and three equivalent Ce(2) atoms to form MgCe4Mg8 cuboctahedra that share corners with six equivalent Mg(1)Ce3Mg9 cuboctahedra, corners with six equivalent Mg(3)Ce4Mg8 cuboctahedra, corners with six equivalent Mg(2)Ce5Mg7 cuboctahedra, edges with two equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with three equivalent Mg(1)Ce3Mg9 cuboctahedra, edges with three equivalent Mg(2)Ce5Mg7 cuboctahedra, edges with four equivalent Ce(1)Ce4Mg8 cuboctahedra, edges with six equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(3)Ce4Mg8 cuboctahedra, faces with three equivalent Mg(1)Ce3Mg9 cuboctahedra, faces with three equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with three equivalent Mg(2)Ce5Mg7 cuboctahedra, faces with four equivalent Ce(1)Ce4Mg8 cuboctahedra, and faces with five equivalent Ce(2)Ce4Mg8 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to one Mg(2), two equivalent Mg(3), two equivalent Mg(4), three equivalent Mg(1), two equivalent Ce(1), and two equivalent Ce(2) atoms to form distorted 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 two equivalent Mg(1)Ce3Mg9 cuboctahedra, edges with three equivalent Ce(1)Ce4Mg8 cuboctahedra, edges with three equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with four equivalent Mg(2)Ce5Mg7 cuboctahedra, edges with six equivalent Mg(3)Ce4Mg8 cuboctahedra, faces with two equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with three equivalent Mg(3)Ce4Mg8 cuboctahedra, faces with three equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with three equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(2)Ce5Mg7 cuboctahedra, and faces with five equivalent Mg(1)Ce3Mg9 cuboctahedra. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Mg(3), two equivalent Mg(1), two equivalent Mg(4), three 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 two equivalent Mg(2)Ce5Mg7 cuboctahedra, edges with three equivalent Mg(4)Ce4Mg8 cuboctahedra, edges with three equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with four equivalent Mg(3)Ce4Mg8 cuboctahedra, edges with six equivalent Mg(1)Ce3Mg9 cuboctahedra, faces with two equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with three equivalent Mg(1)Ce3Mg9 cuboctahedra, faces with three equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with three equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(3)Ce4Mg8 cuboctahedra, and faces with five equivalent Mg(2)Ce5Mg7 cuboctahedra. In the second Ce site, Ce(2) is bonded to one Mg(1), two equivalent Mg(2), two equivalent Mg(4), three 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 two equivalent Mg(3)Ce4Mg8 cuboctahedra, edges with three equivalent Mg(4)Ce4Mg8 cuboctahedra, edges with three equivalent Ce(1)Ce4Mg8 cuboctahedra, edges with four equivalent Mg(1)Ce3Mg9 cuboctahedra, edges with six equivalent Mg(2)Ce5Mg7 cuboctahedra, faces with two equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with three equivalent Mg(4)Ce4Mg8 cuboctahedra, faces with three equivalent Mg(2)Ce5Mg7 cuboctahedra, faces with three equivalent Ce(1)Ce4Mg8 cuboctahedra, faces with four equivalent Mg(1)Ce3Mg9 cuboctahedra, and faces with five equivalent Mg(3)Ce4Mg8 cuboctahedra. is represented by the CIF card [CIF]
data_CeMg2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.579
_cell_length_b   6.579
_cell_length_c   7.849
_cell_angle_alpha   72.701
_cell_angle_beta   72.701
_cell_angle_gamma   28.024
_symmetry_Int_Tables_number   1
_cell_volume   151.945
_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  0.596  0.596  0.309  1.0
  Ce  Ce1  1  0.960  0.960  0.578  1.0
  Mg  Mg2  1  0.996  0.996  0.996  1.0
  Mg  Mg3  1  0.329  0.329  0.322  1.0
  Mg  Mg4  1  0.676  0.676  0.680  1.0
  Mg  Mg5  1  0.277  0.277  0.949  1.0
[/CIF]
.