The compound described by Mg6CoAl crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 3-coordinate geometry to two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Co(1), and two equivalent Al(1) atoms. 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 Al(1) atoms to form distorted MgMg10Al2 cuboctahedra that share corners with four equivalent Al(1)Mg10Co2 cuboctahedra, corners with six equivalent Mg(2)Mg10Al2 cuboctahedra, edges with two equivalent Al(1)Mg10Co2 cuboctahedra, edges with four equivalent Mg(4)Mg10Co2 cuboctahedra, faces with two equivalent Mg(2)Mg10Al2 cuboctahedra, faces with two equivalent Mg(4)Mg10Co2 cuboctahedra, faces with two equivalent Al(1)Mg10Co2 cuboctahedra, and faces with six equivalent Co(1)Mg10Al2 cuboctahedra. In the third Mg site, Mg(3) is bonded in a 12-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Co(1), and two equivalent Al(1) atoms. 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 Co(1) atoms to form distorted MgMg10Co2 cuboctahedra that share corners with four equivalent Co(1)Mg10Al2 cuboctahedra, corners with six equivalent Mg(4)Mg10Co2 cuboctahedra, edges with two equivalent Co(1)Mg10Al2 cuboctahedra, edges with four equivalent Mg(2)Mg10Al2 cuboctahedra, faces with two equivalent Mg(2)Mg10Al2 cuboctahedra, faces with two equivalent Mg(4)Mg10Co2 cuboctahedra, faces with two equivalent Co(1)Mg10Al2 cuboctahedra, and faces with six equivalent Al(1)Mg10Co2 cuboctahedra. Co(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Al(1) atoms to form CoMg10Al2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Co2 cuboctahedra, corners with six equivalent Co(1)Mg10Al2 cuboctahedra, edges with two equivalent Mg(4)Mg10Co2 cuboctahedra, edges with four equivalent Al(1)Mg10Co2 cuboctahedra, faces with two equivalent Mg(4)Mg10Co2 cuboctahedra, faces with two equivalent Co(1)Mg10Al2 cuboctahedra, faces with two equivalent Al(1)Mg10Co2 cuboctahedra, and faces with six equivalent Mg(2)Mg10Al2 cuboctahedra. Al(1) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Co(1) atoms to form distorted AlMg10Co2 cuboctahedra that share corners with four equivalent Mg(2)Mg10Al2 cuboctahedra, corners with six equivalent Al(1)Mg10Co2 cuboctahedra, edges with two equivalent Mg(2)Mg10Al2 cuboctahedra, edges with four equivalent Co(1)Mg10Al2 cuboctahedra, faces with two equivalent Mg(2)Mg10Al2 cuboctahedra, faces with two equivalent Co(1)Mg10Al2 cuboctahedra, faces with two equivalent Al(1)Mg10Co2 cuboctahedra, and faces with six equivalent Mg(4)Mg10Co2 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg6AlCo
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.738
_cell_length_b   6.111
_cell_length_c   6.111
_cell_angle_alpha   119.880
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   153.422
_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
  Al  Al0  1  0.000  0.818  0.182  1.0
  Co  Co1  1  0.500  0.683  0.317  1.0
  Mg  Mg2  1  0.000  0.352  0.176  1.0
  Mg  Mg3  1  0.000  0.824  0.648  1.0
  Mg  Mg4  1  0.000  0.333  0.667  1.0
  Mg  Mg5  1  0.500  0.155  0.331  1.0
  Mg  Mg6  1  0.500  0.669  0.845  1.0
  Mg  Mg7  1  0.500  0.166  0.834  1.0
[/CIF]
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The compound described by Mg6CoAl crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 3-coordinate geometry to two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Co(1), and two equivalent Al(1) atoms. 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 Al(1) atoms to form distorted MgMg10Al2 cuboctahedra that share corners with four equivalent Al(1)Mg10Co2 cuboctahedra, corners with six equivalent Mg(2)Mg10Al2 cuboctahedra, edges with two equivalent Al(1)Mg10Co2 cuboctahedra, edges with four equivalent Mg(4)Mg10Co2 cuboctahedra, faces with two equivalent Mg(2)Mg10Al2 cuboctahedra, faces with two equivalent Mg(4)Mg10Co2 cuboctahedra, faces with two equivalent Al(1)Mg10Co2 cuboctahedra, and faces with six equivalent Co(1)Mg10Al2 cuboctahedra. In the third Mg site, Mg(3) is bonded in a 12-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Co(1), and two equivalent Al(1) atoms. 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 Co(1) atoms to form distorted MgMg10Co2 cuboctahedra that share corners with four equivalent Co(1)Mg10Al2 cuboctahedra, corners with six equivalent Mg(4)Mg10Co2 cuboctahedra, edges with two equivalent Co(1)Mg10Al2 cuboctahedra, edges with four equivalent Mg(2)Mg10Al2 cuboctahedra, faces with two equivalent Mg(2)Mg10Al2 cuboctahedra, faces with two equivalent Mg(4)Mg10Co2 cuboctahedra, faces with two equivalent Co(1)Mg10Al2 cuboctahedra, and faces with six equivalent Al(1)Mg10Co2 cuboctahedra. Co(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Al(1) atoms to form CoMg10Al2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Co2 cuboctahedra, corners with six equivalent Co(1)Mg10Al2 cuboctahedra, edges with two equivalent Mg(4)Mg10Co2 cuboctahedra, edges with four equivalent Al(1)Mg10Co2 cuboctahedra, faces with two equivalent Mg(4)Mg10Co2 cuboctahedra, faces with two equivalent Co(1)Mg10Al2 cuboctahedra, faces with two equivalent Al(1)Mg10Co2 cuboctahedra, and faces with six equivalent Mg(2)Mg10Al2 cuboctahedra. Al(1) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Co(1) atoms to form distorted AlMg10Co2 cuboctahedra that share corners with four equivalent Mg(2)Mg10Al2 cuboctahedra, corners with six equivalent Al(1)Mg10Co2 cuboctahedra, edges with two equivalent Mg(2)Mg10Al2 cuboctahedra, edges with four equivalent Co(1)Mg10Al2 cuboctahedra, faces with two equivalent Mg(2)Mg10Al2 cuboctahedra, faces with two equivalent Co(1)Mg10Al2 cuboctahedra, faces with two equivalent Al(1)Mg10Co2 cuboctahedra, and faces with six equivalent Mg(4)Mg10Co2 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg6AlCo
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.738
_cell_length_b   6.111
_cell_length_c   6.111
_cell_angle_alpha   119.880
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   153.422
_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
  Al  Al0  1  0.000  0.818  0.182  1.0
  Co  Co1  1  0.500  0.683  0.317  1.0
  Mg  Mg2  1  0.000  0.352  0.176  1.0
  Mg  Mg3  1  0.000  0.824  0.648  1.0
  Mg  Mg4  1  0.000  0.333  0.667  1.0
  Mg  Mg5  1  0.500  0.155  0.331  1.0
  Mg  Mg6  1  0.500  0.669  0.845  1.0
  Mg  Mg7  1  0.500  0.166  0.834  1.0
[/CIF]
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