The material structure described by Mg6ZrNb is beta Cu3Ti-derived structured and 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 Zr(1), and two equivalent Nb(1) atoms to form MgMg8Zr2Nb2 cuboctahedra that share corners with four equivalent Zr(1)Mg10Nb2 cuboctahedra, corners with four equivalent Nb(1)Mg10Zr2 cuboctahedra, corners with ten equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, edges with two equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, edges with two equivalent Zr(1)Mg10Nb2 cuboctahedra, edges with two equivalent Nb(1)Mg10Zr2 cuboctahedra, edges with four equivalent Mg(3)Mg10Zr2 cuboctahedra, edges with four equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, faces with two equivalent Mg(3)Mg10Zr2 cuboctahedra, faces with two equivalent Zr(1)Mg10Nb2 cuboctahedra, faces with two equivalent Nb(1)Mg10Zr2 cuboctahedra, faces with four equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, and faces with eight equivalent Mg(2)Mg8Zr2Nb2 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), two equivalent Zr(1), and two equivalent Nb(1) atoms to form distorted MgMg8Zr2Nb2 cuboctahedra that share corners with four equivalent Mg(3)Mg10Zr2 cuboctahedra, corners with ten equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, edges with two equivalent Mg(3)Mg10Zr2 cuboctahedra, edges with two equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, edges with four equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, edges with four equivalent Zr(1)Mg10Nb2 cuboctahedra, edges with four equivalent Nb(1)Mg10Zr2 cuboctahedra, faces with two equivalent Mg(3)Mg10Zr2 cuboctahedra, faces with two equivalent Zr(1)Mg10Nb2 cuboctahedra, faces with two equivalent Nb(1)Mg10Zr2 cuboctahedra, faces with four equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, and faces with eight equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Zr(1) atoms to form MgMg10Zr2 cuboctahedra that share corners with six equivalent Mg(3)Mg10Zr2 cuboctahedra, corners with eight equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, edges with four equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, edges with four equivalent Zr(1)Mg10Nb2 cuboctahedra, edges with eight equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, faces with two equivalent Mg(3)Mg10Zr2 cuboctahedra, faces with two equivalent Zr(1)Mg10Nb2 cuboctahedra, faces with four equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, faces with four equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, and faces with six equivalent Nb(1)Mg10Zr2 cuboctahedra. In the fourth Mg site, Mg(4) is bonded in a 12-coordinate geometry to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Nb(1) atoms. Zr(1) is bonded to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Nb(1) atoms to form distorted ZrMg10Nb2 cuboctahedra that share corners with four equivalent Nb(1)Mg10Zr2 cuboctahedra, corners with six equivalent Zr(1)Mg10Nb2 cuboctahedra, corners with eight equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, edges with two equivalent Nb(1)Mg10Zr2 cuboctahedra, edges with four equivalent Mg(3)Mg10Zr2 cuboctahedra, edges with four equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, edges with eight equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, faces with two equivalent Mg(3)Mg10Zr2 cuboctahedra, faces with two equivalent Zr(1)Mg10Nb2 cuboctahedra, faces with two equivalent Nb(1)Mg10Zr2 cuboctahedra, faces with four equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, and faces with four equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra. Nb(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Zr(1) atoms to form NbMg10Zr2 cuboctahedra that share corners with four equivalent Zr(1)Mg10Nb2 cuboctahedra, corners with six equivalent Nb(1)Mg10Zr2 cuboctahedra, corners with eight equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, edges with two equivalent Zr(1)Mg10Nb2 cuboctahedra, edges with four equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, edges with eight equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, faces with two equivalent Zr(1)Mg10Nb2 cuboctahedra, faces with two equivalent Nb(1)Mg10Zr2 cuboctahedra, faces with four equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, faces with four equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, and faces with six equivalent Mg(3)Mg10Zr2 cuboctahedra. is represented by the CIF file [CIF]
data_Mg6ZrNb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.105
_cell_length_b   5.864
_cell_length_c   6.460
_cell_angle_alpha   116.995
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   172.304
_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  0.500  0.673  0.847  1.0
  Mg  Mg1  1  0.500  0.173  0.847  1.0
  Mg  Mg2  1  1.000  0.828  0.166  1.0
  Mg  Mg3  1  1.000  0.338  0.166  1.0
  Mg  Mg4  1  0.000  0.326  0.651  1.0
  Mg  Mg5  1  0.000  0.817  0.633  1.0
  Nb  Nb6  1  0.500  0.671  0.342  1.0
  Zr  Zr7  1  0.500  0.173  0.347  1.0
[/CIF]
.
The material structure described by Mg6ZrNb is beta Cu3Ti-derived structured and 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 Zr(1), and two equivalent Nb(1) atoms to form MgMg8Zr2Nb2 cuboctahedra that share corners with four equivalent Zr(1)Mg10Nb2 cuboctahedra, corners with four equivalent Nb(1)Mg10Zr2 cuboctahedra, corners with ten equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, edges with two equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, edges with two equivalent Zr(1)Mg10Nb2 cuboctahedra, edges with two equivalent Nb(1)Mg10Zr2 cuboctahedra, edges with four equivalent Mg(3)Mg10Zr2 cuboctahedra, edges with four equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, faces with two equivalent Mg(3)Mg10Zr2 cuboctahedra, faces with two equivalent Zr(1)Mg10Nb2 cuboctahedra, faces with two equivalent Nb(1)Mg10Zr2 cuboctahedra, faces with four equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, and faces with eight equivalent Mg(2)Mg8Zr2Nb2 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), two equivalent Zr(1), and two equivalent Nb(1) atoms to form distorted MgMg8Zr2Nb2 cuboctahedra that share corners with four equivalent Mg(3)Mg10Zr2 cuboctahedra, corners with ten equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, edges with two equivalent Mg(3)Mg10Zr2 cuboctahedra, edges with two equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, edges with four equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, edges with four equivalent Zr(1)Mg10Nb2 cuboctahedra, edges with four equivalent Nb(1)Mg10Zr2 cuboctahedra, faces with two equivalent Mg(3)Mg10Zr2 cuboctahedra, faces with two equivalent Zr(1)Mg10Nb2 cuboctahedra, faces with two equivalent Nb(1)Mg10Zr2 cuboctahedra, faces with four equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, and faces with eight equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Zr(1) atoms to form MgMg10Zr2 cuboctahedra that share corners with six equivalent Mg(3)Mg10Zr2 cuboctahedra, corners with eight equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, edges with four equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, edges with four equivalent Zr(1)Mg10Nb2 cuboctahedra, edges with eight equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, faces with two equivalent Mg(3)Mg10Zr2 cuboctahedra, faces with two equivalent Zr(1)Mg10Nb2 cuboctahedra, faces with four equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, faces with four equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, and faces with six equivalent Nb(1)Mg10Zr2 cuboctahedra. In the fourth Mg site, Mg(4) is bonded in a 12-coordinate geometry to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Nb(1) atoms. Zr(1) is bonded to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Nb(1) atoms to form distorted ZrMg10Nb2 cuboctahedra that share corners with four equivalent Nb(1)Mg10Zr2 cuboctahedra, corners with six equivalent Zr(1)Mg10Nb2 cuboctahedra, corners with eight equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, edges with two equivalent Nb(1)Mg10Zr2 cuboctahedra, edges with four equivalent Mg(3)Mg10Zr2 cuboctahedra, edges with four equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, edges with eight equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, faces with two equivalent Mg(3)Mg10Zr2 cuboctahedra, faces with two equivalent Zr(1)Mg10Nb2 cuboctahedra, faces with two equivalent Nb(1)Mg10Zr2 cuboctahedra, faces with four equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, and faces with four equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra. Nb(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Zr(1) atoms to form NbMg10Zr2 cuboctahedra that share corners with four equivalent Zr(1)Mg10Nb2 cuboctahedra, corners with six equivalent Nb(1)Mg10Zr2 cuboctahedra, corners with eight equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, edges with two equivalent Zr(1)Mg10Nb2 cuboctahedra, edges with four equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, edges with eight equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, faces with two equivalent Zr(1)Mg10Nb2 cuboctahedra, faces with two equivalent Nb(1)Mg10Zr2 cuboctahedra, faces with four equivalent Mg(1)Mg8Zr2Nb2 cuboctahedra, faces with four equivalent Mg(2)Mg8Zr2Nb2 cuboctahedra, and faces with six equivalent Mg(3)Mg10Zr2 cuboctahedra. is represented by the CIF file [CIF]
data_Mg6ZrNb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.105
_cell_length_b   5.864
_cell_length_c   6.460
_cell_angle_alpha   116.995
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   172.304
_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  0.500  0.673  0.847  1.0
  Mg  Mg1  1  0.500  0.173  0.847  1.0
  Mg  Mg2  1  1.000  0.828  0.166  1.0
  Mg  Mg3  1  1.000  0.338  0.166  1.0
  Mg  Mg4  1  0.000  0.326  0.651  1.0
  Mg  Mg5  1  0.000  0.817  0.633  1.0
  Nb  Nb6  1  0.500  0.671  0.342  1.0
  Zr  Zr7  1  0.500  0.173  0.347  1.0
[/CIF]
.