The crystal structure described by Mg6NiSb 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), two equivalent Mg(4), two equivalent Ni(1), and two equivalent Sb(1) atoms to form distorted MgMg8Ni2Sb2 cuboctahedra that share corners with four equivalent Mg(2)Mg10Ni2 cuboctahedra, corners with four equivalent Ni(1)Mg10Sb2 cuboctahedra, corners with ten equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, edges with two equivalent Mg(2)Mg10Ni2 cuboctahedra, edges with two equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, edges with two equivalent Ni(1)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, edges with four equivalent Sb(1)Mg10Ni2 cuboctahedra, faces with two equivalent Mg(2)Mg10Ni2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Ni(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Ni2 cuboctahedra, faces with four equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, and faces with eight equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Ni(1) atoms to form distorted MgMg10Ni2 cuboctahedra that share corners with four equivalent Ni(1)Mg10Sb2 cuboctahedra, corners with six equivalent Mg(2)Mg10Ni2 cuboctahedra, corners with eight equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, edges with two equivalent Ni(1)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, edges with eight equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, faces with two equivalent Mg(2)Mg10Ni2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Ni(1)Mg10Sb2 cuboctahedra, faces with four equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, faces with four equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, and faces with six equivalent Sb(1)Mg10Ni2 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), two equivalent Ni(1), and two equivalent Sb(1) atoms to form distorted MgMg8Ni2Sb2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Sb2 cuboctahedra, corners with four equivalent Sb(1)Mg10Ni2 cuboctahedra, corners with ten equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, edges with two equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with two equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, edges with two equivalent Sb(1)Mg10Ni2 cuboctahedra, edges with four equivalent Mg(2)Mg10Ni2 cuboctahedra, edges with four equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, edges with four equivalent Ni(1)Mg10Sb2 cuboctahedra, faces with two equivalent Mg(2)Mg10Ni2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Ni(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Ni2 cuboctahedra, faces with four equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, and faces with eight equivalent Mg(1)Mg8Ni2Sb2 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 Sb(1) atoms to form distorted MgMg10Sb2 cuboctahedra that share corners with four equivalent Sb(1)Mg10Ni2 cuboctahedra, corners with six equivalent Mg(4)Mg10Sb2 cuboctahedra, corners with eight equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, edges with two equivalent Sb(1)Mg10Ni2 cuboctahedra, edges with four equivalent Mg(2)Mg10Ni2 cuboctahedra, edges with four equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, edges with eight equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, faces with two equivalent Mg(2)Mg10Ni2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Ni2 cuboctahedra, faces with four equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, faces with four equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, and faces with six equivalent Ni(1)Mg10Sb2 cuboctahedra. Ni(1) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Sb(1) atoms to form NiMg10Sb2 cuboctahedra that share corners with four equivalent Mg(2)Mg10Ni2 cuboctahedra, corners with six equivalent Ni(1)Mg10Sb2 cuboctahedra, corners with eight equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, edges with two equivalent Mg(2)Mg10Ni2 cuboctahedra, edges with four equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, edges with four equivalent Sb(1)Mg10Ni2 cuboctahedra, edges with eight equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, faces with two equivalent Mg(2)Mg10Ni2 cuboctahedra, faces with two equivalent Ni(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Ni2 cuboctahedra, faces with four equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, faces with four equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, and faces with six equivalent Mg(4)Mg10Sb2 cuboctahedra. Sb(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Ni(1) atoms to form SbMg10Ni2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Sb2 cuboctahedra, corners with six equivalent Sb(1)Mg10Ni2 cuboctahedra, corners with eight equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, edges with two equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, edges with four equivalent Ni(1)Mg10Sb2 cuboctahedra, edges with eight equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Ni(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Ni2 cuboctahedra, faces with four equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, faces with four equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, and faces with six equivalent Mg(2)Mg10Ni2 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg6NiSb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.152
_cell_length_b   6.152
_cell_length_c   5.033
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   119.875
_symmetry_Int_Tables_number   1
_cell_volume   165.179
_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
  Mg  Mg0  1  0.828  0.663  0.500  1.0
  Mg  Mg1  1  0.337  0.172  0.500  1.0
  Mg  Mg2  1  0.833  0.167  0.500  1.0
  Mg  Mg3  1  0.657  0.830  0.000  1.0
  Mg  Mg4  1  0.170  0.343  0.000  1.0
  Mg  Mg5  1  0.668  0.332  0.000  1.0
  Ni  Ni6  1  0.336  0.664  0.500  1.0
  Sb  Sb7  1  0.171  0.829  0.000  1.0
[/CIF]
.
The crystal structure described by Mg6NiSb 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), two equivalent Mg(4), two equivalent Ni(1), and two equivalent Sb(1) atoms to form distorted MgMg8Ni2Sb2 cuboctahedra that share corners with four equivalent Mg(2)Mg10Ni2 cuboctahedra, corners with four equivalent Ni(1)Mg10Sb2 cuboctahedra, corners with ten equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, edges with two equivalent Mg(2)Mg10Ni2 cuboctahedra, edges with two equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, edges with two equivalent Ni(1)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, edges with four equivalent Sb(1)Mg10Ni2 cuboctahedra, faces with two equivalent Mg(2)Mg10Ni2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Ni(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Ni2 cuboctahedra, faces with four equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, and faces with eight equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Ni(1) atoms to form distorted MgMg10Ni2 cuboctahedra that share corners with four equivalent Ni(1)Mg10Sb2 cuboctahedra, corners with six equivalent Mg(2)Mg10Ni2 cuboctahedra, corners with eight equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, edges with two equivalent Ni(1)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, edges with eight equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, faces with two equivalent Mg(2)Mg10Ni2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Ni(1)Mg10Sb2 cuboctahedra, faces with four equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, faces with four equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, and faces with six equivalent Sb(1)Mg10Ni2 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), two equivalent Ni(1), and two equivalent Sb(1) atoms to form distorted MgMg8Ni2Sb2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Sb2 cuboctahedra, corners with four equivalent Sb(1)Mg10Ni2 cuboctahedra, corners with ten equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, edges with two equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with two equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, edges with two equivalent Sb(1)Mg10Ni2 cuboctahedra, edges with four equivalent Mg(2)Mg10Ni2 cuboctahedra, edges with four equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, edges with four equivalent Ni(1)Mg10Sb2 cuboctahedra, faces with two equivalent Mg(2)Mg10Ni2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Ni(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Ni2 cuboctahedra, faces with four equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, and faces with eight equivalent Mg(1)Mg8Ni2Sb2 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 Sb(1) atoms to form distorted MgMg10Sb2 cuboctahedra that share corners with four equivalent Sb(1)Mg10Ni2 cuboctahedra, corners with six equivalent Mg(4)Mg10Sb2 cuboctahedra, corners with eight equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, edges with two equivalent Sb(1)Mg10Ni2 cuboctahedra, edges with four equivalent Mg(2)Mg10Ni2 cuboctahedra, edges with four equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, edges with eight equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, faces with two equivalent Mg(2)Mg10Ni2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Ni2 cuboctahedra, faces with four equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, faces with four equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, and faces with six equivalent Ni(1)Mg10Sb2 cuboctahedra. Ni(1) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Sb(1) atoms to form NiMg10Sb2 cuboctahedra that share corners with four equivalent Mg(2)Mg10Ni2 cuboctahedra, corners with six equivalent Ni(1)Mg10Sb2 cuboctahedra, corners with eight equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, edges with two equivalent Mg(2)Mg10Ni2 cuboctahedra, edges with four equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, edges with four equivalent Sb(1)Mg10Ni2 cuboctahedra, edges with eight equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, faces with two equivalent Mg(2)Mg10Ni2 cuboctahedra, faces with two equivalent Ni(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Ni2 cuboctahedra, faces with four equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, faces with four equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, and faces with six equivalent Mg(4)Mg10Sb2 cuboctahedra. Sb(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Ni(1) atoms to form SbMg10Ni2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Sb2 cuboctahedra, corners with six equivalent Sb(1)Mg10Ni2 cuboctahedra, corners with eight equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, edges with two equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, edges with four equivalent Ni(1)Mg10Sb2 cuboctahedra, edges with eight equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Ni(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Ni2 cuboctahedra, faces with four equivalent Mg(1)Mg8Ni2Sb2 cuboctahedra, faces with four equivalent Mg(3)Mg8Ni2Sb2 cuboctahedra, and faces with six equivalent Mg(2)Mg10Ni2 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg6NiSb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.152
_cell_length_b   6.152
_cell_length_c   5.033
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   119.875
_symmetry_Int_Tables_number   1
_cell_volume   165.179
_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
  Mg  Mg0  1  0.828  0.663  0.500  1.0
  Mg  Mg1  1  0.337  0.172  0.500  1.0
  Mg  Mg2  1  0.833  0.167  0.500  1.0
  Mg  Mg3  1  0.657  0.830  0.000  1.0
  Mg  Mg4  1  0.170  0.343  0.000  1.0
  Mg  Mg5  1  0.668  0.332  0.000  1.0
  Ni  Ni6  1  0.336  0.664  0.500  1.0
  Sb  Sb7  1  0.171  0.829  0.000  1.0
[/CIF]
.