data_MgIr2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.03
_cell_length_b   6.03
_cell_length_c   6.03
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgIr2
_chemical_formula_sum   'Mg4 Ir8'
_cell_volume   219.76
_cell_formula_units_Z   4
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  Mg8  1  0.0  0.0  0.0  1.0
  Mg  Mg9  1  0.0  0.02  0.02  1.0
  Mg  Mg10  1  0.02  0.0  0.02  1.0
  Mg  Mg11  1  0.02  0.02  0.0  1.0
  Ir  Ir0  1  0.69  0.71  0.35  1.0
  Ir  Ir1  1  0.69  0.35  0.33  1.0
  Ir  Ir2  1  0.33  0.69  0.35  1.0
  Ir  Ir3  1  0.33  0.33  0.33  1.0
  Ir  Ir4  1  0.71  0.71  0.71  1.0
  Ir  Ir5  1  0.71  0.35  0.69  1.0
  Ir  Ir6  1  0.35  0.69  0.71  1.0
  Ir  Ir7  1  0.35  0.33  0.69  1.0

data_MgIr2
_symmetry_space_group_name_H-M   R3
_cell_length_a   8.53
_cell_length_b   8.53
_cell_length_c   10.45
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   146
_chemical_formula_structural   MgIr2
_chemical_formula_sum   'Mg12 Ir24'
_cell_volume   659.28
_cell_formula_units_Z   12
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  'x+1/3, y+2/3, z+2/3'
  5  '-y+1/3, x-y+2/3, z+2/3'
  6  '-x+y+1/3, -x+2/3, z+2/3'
  7  'x+2/3, y+1/3, z+1/3'
  8  '-y+2/3, x-y+1/3, z+1/3'
  9  '-x+y+2/3, -x+1/3, z+1/3'
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  9  0.01  0.01  0.01  1.0
  Mg  Mg1  3  0.0  0.0  0.0  1.0
  Ir  Ir2  9  0.1  0.54  0.25  1.0
  Ir  Ir3  9  0.21  0.78  0.12  1.0
  Ir  Ir4  3  0.0  0.0  0.33  1.0
  Ir  Ir5  3  0.0  0.0  0.71  1.0

Mg Mg Mg Mg Ir Ir Ir Ir Ir Ir Ir Ir
MgIr2 crystallizes in the trigonal R3 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate geometry to three equivalent Mg(2) and one Ir(4) atom. All Mg(1)-Mg(2) bond lengths are 0.15 Å. The Mg(1)-Ir(4) bond length is 3.07 Å. In the second Mg site, Mg(2) is bonded in a 3-coordinate geometry to one Mg(1), two equivalent Mg(2), and one Ir(2) atom. Both Mg(2)-Mg(2) bond lengths are 0.15 Å. The Mg(2)-Ir(2) bond length is 3.31 Å. There are four inequivalent Ir sites. In the first Ir site, Ir(1) is bonded in a 3-coordinate geometry to one Ir(4) and two equivalent Ir(2) atoms. The Ir(1)-Ir(4) bond length is 2.18 Å. Both Ir(1)-Ir(2) bond lengths are 2.18 Å. In the second Ir site, Ir(2) is bonded in a rectangular see-saw-like geometry to one Mg(2), one Ir(3), and two equivalent Ir(1) atoms. The Ir(2)-Ir(3) bond length is 2.18 Å. In the third Ir site, Ir(3) is bonded in a 3-coordinate geometry to three equivalent Ir(2) atoms. In the fourth Ir site, Ir(4) is bonded in a rectangular see-saw-like geometry to one Mg(1) and three equivalent Ir(1) atoms.