The structure described by NaMg6Cr is beta Cu3Ti-derived structured and crystallizes in the orthorhombic Amm2 space group. Na(1) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Cr(1) atoms to form NaMg10Cr2 cuboctahedra that share corners with four equivalent Mg(2)Na2Mg10 cuboctahedra, corners with six equivalent Na(1)Mg10Cr2 cuboctahedra, corners with eight equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, edges with two equivalent Mg(2)Na2Mg10 cuboctahedra, edges with four equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, edges with four equivalent Cr(1)Na2Mg10 cuboctahedra, edges with eight equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, faces with two equivalent Na(1)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(2)Na2Mg10 cuboctahedra, faces with two equivalent Cr(1)Na2Mg10 cuboctahedra, faces with four equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, faces with four equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, and faces with six equivalent Mg(4)Mg10Cr2 cuboctahedra. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Cr(1) atoms to form distorted MgNa2Mg8Cr2 cuboctahedra that share corners with four equivalent Na(1)Mg10Cr2 cuboctahedra, corners with four equivalent Mg(2)Na2Mg10 cuboctahedra, corners with ten equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, edges with two equivalent Na(1)Mg10Cr2 cuboctahedra, edges with two equivalent Mg(2)Na2Mg10 cuboctahedra, edges with two equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, edges with four equivalent Mg(4)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, edges with four equivalent Cr(1)Na2Mg10 cuboctahedra, faces with two equivalent Na(1)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(2)Na2Mg10 cuboctahedra, faces with two equivalent Cr(1)Na2Mg10 cuboctahedra, faces with four equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, and faces with eight equivalent Mg(3)Na2Mg8Cr2 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Na(1), two equivalent Mg(4), four equivalent Mg(1), and four equivalent Mg(3) atoms to form distorted MgNa2Mg10 cuboctahedra that share corners with four equivalent Na(1)Mg10Cr2 cuboctahedra, corners with six equivalent Mg(2)Na2Mg10 cuboctahedra, corners with eight equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, edges with two equivalent Na(1)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(4)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, edges with eight equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, faces with two equivalent Na(1)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(2)Na2Mg10 cuboctahedra, faces with four equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, faces with four equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, and faces with six equivalent Cr(1)Na2Mg10 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Cr(1) atoms to form distorted MgNa2Mg8Cr2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Cr2 cuboctahedra, corners with four equivalent Cr(1)Na2Mg10 cuboctahedra, corners with ten equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, edges with two equivalent Mg(4)Mg10Cr2 cuboctahedra, edges with two equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, edges with two equivalent Cr(1)Na2Mg10 cuboctahedra, edges with four equivalent Na(1)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(2)Na2Mg10 cuboctahedra, edges with four equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, faces with two equivalent Na(1)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(2)Na2Mg10 cuboctahedra, faces with two equivalent Cr(1)Na2Mg10 cuboctahedra, faces with four equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, and faces with eight equivalent Mg(1)Na2Mg8Cr2 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Cr(1) atoms to form MgMg10Cr2 cuboctahedra that share corners with four equivalent Cr(1)Na2Mg10 cuboctahedra, corners with six equivalent Mg(4)Mg10Cr2 cuboctahedra, corners with eight equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, edges with two equivalent Cr(1)Na2Mg10 cuboctahedra, edges with four equivalent Mg(2)Na2Mg10 cuboctahedra, edges with four equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, edges with eight equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(2)Na2Mg10 cuboctahedra, faces with two equivalent Cr(1)Na2Mg10 cuboctahedra, faces with four equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, faces with four equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, and faces with six equivalent Na(1)Mg10Cr2 cuboctahedra. Cr(1) is bonded to two equivalent Na(1), two equivalent Mg(4), four equivalent Mg(1), and four equivalent Mg(3) atoms to form CrNa2Mg10 cuboctahedra that share corners with four equivalent Mg(4)Mg10Cr2 cuboctahedra, corners with six equivalent Cr(1)Na2Mg10 cuboctahedra, corners with eight equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, edges with two equivalent Mg(4)Mg10Cr2 cuboctahedra, edges with four equivalent Na(1)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, edges with eight equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, faces with two equivalent Na(1)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Cr(1)Na2Mg10 cuboctahedra, faces with four equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, faces with four equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, and faces with six equivalent Mg(2)Na2Mg10 cuboctahedra. is represented by the CIF card [CIF]
data_NaMg6Cr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.192
_cell_length_b   6.363
_cell_length_c   6.385
_cell_angle_alpha   119.887
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   182.889
_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
  Cr  Cr0  1  0.500  0.660  0.320  1.0
  Mg  Mg1  1  1.000  0.829  0.173  1.0
  Mg  Mg2  1  1.000  0.345  0.173  1.0
  Mg  Mg3  1  0.000  0.333  0.666  1.0
  Mg  Mg4  1  0.500  0.665  0.836  1.0
  Mg  Mg5  1  0.500  0.170  0.836  1.0
  Mg  Mg6  1  0.500  0.166  0.332  1.0
  Na  Na7  1  0.000  0.832  0.664  1.0
[/CIF]
.
The structure described by NaMg6Cr is beta Cu3Ti-derived structured and crystallizes in the orthorhombic Amm2 space group. Na(1) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Cr(1) atoms to form NaMg10Cr2 cuboctahedra that share corners with four equivalent Mg(2)Na2Mg10 cuboctahedra, corners with six equivalent Na(1)Mg10Cr2 cuboctahedra, corners with eight equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, edges with two equivalent Mg(2)Na2Mg10 cuboctahedra, edges with four equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, edges with four equivalent Cr(1)Na2Mg10 cuboctahedra, edges with eight equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, faces with two equivalent Na(1)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(2)Na2Mg10 cuboctahedra, faces with two equivalent Cr(1)Na2Mg10 cuboctahedra, faces with four equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, faces with four equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, and faces with six equivalent Mg(4)Mg10Cr2 cuboctahedra. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Cr(1) atoms to form distorted MgNa2Mg8Cr2 cuboctahedra that share corners with four equivalent Na(1)Mg10Cr2 cuboctahedra, corners with four equivalent Mg(2)Na2Mg10 cuboctahedra, corners with ten equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, edges with two equivalent Na(1)Mg10Cr2 cuboctahedra, edges with two equivalent Mg(2)Na2Mg10 cuboctahedra, edges with two equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, edges with four equivalent Mg(4)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, edges with four equivalent Cr(1)Na2Mg10 cuboctahedra, faces with two equivalent Na(1)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(2)Na2Mg10 cuboctahedra, faces with two equivalent Cr(1)Na2Mg10 cuboctahedra, faces with four equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, and faces with eight equivalent Mg(3)Na2Mg8Cr2 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Na(1), two equivalent Mg(4), four equivalent Mg(1), and four equivalent Mg(3) atoms to form distorted MgNa2Mg10 cuboctahedra that share corners with four equivalent Na(1)Mg10Cr2 cuboctahedra, corners with six equivalent Mg(2)Na2Mg10 cuboctahedra, corners with eight equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, edges with two equivalent Na(1)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(4)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, edges with eight equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, faces with two equivalent Na(1)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(2)Na2Mg10 cuboctahedra, faces with four equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, faces with four equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, and faces with six equivalent Cr(1)Na2Mg10 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Cr(1) atoms to form distorted MgNa2Mg8Cr2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Cr2 cuboctahedra, corners with four equivalent Cr(1)Na2Mg10 cuboctahedra, corners with ten equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, edges with two equivalent Mg(4)Mg10Cr2 cuboctahedra, edges with two equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, edges with two equivalent Cr(1)Na2Mg10 cuboctahedra, edges with four equivalent Na(1)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(2)Na2Mg10 cuboctahedra, edges with four equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, faces with two equivalent Na(1)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(2)Na2Mg10 cuboctahedra, faces with two equivalent Cr(1)Na2Mg10 cuboctahedra, faces with four equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, and faces with eight equivalent Mg(1)Na2Mg8Cr2 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Cr(1) atoms to form MgMg10Cr2 cuboctahedra that share corners with four equivalent Cr(1)Na2Mg10 cuboctahedra, corners with six equivalent Mg(4)Mg10Cr2 cuboctahedra, corners with eight equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, edges with two equivalent Cr(1)Na2Mg10 cuboctahedra, edges with four equivalent Mg(2)Na2Mg10 cuboctahedra, edges with four equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, edges with eight equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(2)Na2Mg10 cuboctahedra, faces with two equivalent Cr(1)Na2Mg10 cuboctahedra, faces with four equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, faces with four equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, and faces with six equivalent Na(1)Mg10Cr2 cuboctahedra. Cr(1) is bonded to two equivalent Na(1), two equivalent Mg(4), four equivalent Mg(1), and four equivalent Mg(3) atoms to form CrNa2Mg10 cuboctahedra that share corners with four equivalent Mg(4)Mg10Cr2 cuboctahedra, corners with six equivalent Cr(1)Na2Mg10 cuboctahedra, corners with eight equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, edges with two equivalent Mg(4)Mg10Cr2 cuboctahedra, edges with four equivalent Na(1)Mg10Cr2 cuboctahedra, edges with four equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, edges with eight equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, faces with two equivalent Na(1)Mg10Cr2 cuboctahedra, faces with two equivalent Mg(4)Mg10Cr2 cuboctahedra, faces with two equivalent Cr(1)Na2Mg10 cuboctahedra, faces with four equivalent Mg(1)Na2Mg8Cr2 cuboctahedra, faces with four equivalent Mg(3)Na2Mg8Cr2 cuboctahedra, and faces with six equivalent Mg(2)Na2Mg10 cuboctahedra. is represented by the CIF card [CIF]
data_NaMg6Cr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.192
_cell_length_b   6.363
_cell_length_c   6.385
_cell_angle_alpha   119.887
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   182.889
_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
  Cr  Cr0  1  0.500  0.660  0.320  1.0
  Mg  Mg1  1  1.000  0.829  0.173  1.0
  Mg  Mg2  1  1.000  0.345  0.173  1.0
  Mg  Mg3  1  0.000  0.333  0.666  1.0
  Mg  Mg4  1  0.500  0.665  0.836  1.0
  Mg  Mg5  1  0.500  0.170  0.836  1.0
  Mg  Mg6  1  0.500  0.166  0.332  1.0
  Na  Na7  1  0.000  0.832  0.664  1.0
[/CIF]
.