data_MgCuOs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.03
_cell_length_b   9.03
_cell_length_c   9.03
_cell_angle_alpha   17.66
_cell_angle_beta   17.66
_cell_angle_gamma   17.66
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgCuOs2
_chemical_formula_sum   'Mg1 Cu1 Os2'
_cell_volume   59.19
_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  Mg1  1  0.0  0.0  0.02  1.0
  Cu  Cu0  1  0.0  0.0  0.39  1.0
  Os  Os2  1  0.0  0.0  0.56  1.0
  Os  Os3  1  0.0  0.0  0.71  1.0

data_MgCuOs2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.8
_cell_length_b   2.77
_cell_length_c   9.03
_cell_angle_alpha   90.0
_cell_angle_beta   100.21
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   MgCuOs2
_chemical_formula_sum   'Mg2 Cu2 Os4'
_cell_volume   118.38
_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  0.0  0.0  0.98  1.0
  Cu  Cu1  2  0.0  0.0  0.61  1.0
  Os  Os2  2  0.0  0.0  0.29  1.0
  Os  Os3  2  0.0  0.0  0.44  1.0

Mg Cu Os Os
MgOs2Cu crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a 8-coordinate geometry to six equivalent Mg(1), one Os(2), and one Cu(1) atom. All Mg(1)-Mg(1) bond lengths are 2.77 Å. The Mg(1)-Os(2) bond length is 2.87 Å. The Mg(1)-Cu(1) bond length is 3.26 Å. There are two inequivalent Os sites. In the first Os site, Os(1) is bonded in a linear geometry to one Os(2) and one Cu(1) atom. The Os(1)-Os(2) bond length is 1.33 Å. The Os(1)-Cu(1) bond length is 1.58 Å. In the second Os site, Os(2) is bonded in a distorted linear geometry to one Mg(1) and one Os(1) atom. Cu(1) is bonded in a single-bond geometry to one Mg(1) and one Os(1) atom.