data_Mg2AsIr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.03
_cell_length_b   3.03
_cell_length_c   7.59
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2AsIr
_chemical_formula_sum   'Mg2 As1 Ir1'
_cell_volume   69.74
_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  Mg2  1  0.52  0.52  0.46  1.0
  Mg  Mg3  1  0.52  0.52  0.13  1.0
  As  As0  1  0.0  0.0  0.0  1.0
  Ir  Ir1  1  0.0  0.0  0.8  1.0

data_Mg2AsIr
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.29
_cell_length_b   4.29
_cell_length_c   7.59
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Mg2AsIr
_chemical_formula_sum   'Mg4 As2 Ir2'
_cell_volume   139.48
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.02  0.5  0.13  1.0
  Mg  Mg1  2  0.02  0.5  0.46  1.0
  As  As2  2  0.0  0.0  0.0  1.0
  Ir  Ir3  2  0.0  0.0  0.8  1.0

Mg Mg As Ir
Mg2IrAs crystallizes in the monoclinic Cm space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 9-coordinate geometry to one Mg(2), four equivalent Mg(1), and four equivalent Ir(1) atoms. The Mg(1)-Mg(2) bond length is 2.47 Å. All Mg(1)-Mg(1) bond lengths are 3.03 Å. There are a spread of Mg(1)-Ir(1) bond distances ranging from 3.30-3.38 Å. In the second Mg site, Mg(2) is bonded in a 4-coordinate geometry to one Mg(1) and four equivalent As(1) atoms. There are a spread of Mg(2)-As(1) bond distances ranging from 2.31-2.43 Å. Ir(1) is bonded in a distorted single-bond geometry to four equivalent Mg(1) and one As(1) atom. The Ir(1)-As(1) bond length is 1.55 Å. As(1) is bonded in a 5-coordinate geometry to four equivalent Mg(2) and one Ir(1) atom.