data_Mg3ReRh
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.76
_cell_length_b   4.76
_cell_length_c   4.76
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg3ReRh
_chemical_formula_sum   'Mg3 Re1 Rh1'
_cell_volume   107.77
_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  0.38  0.0  1.0
  Mg  Mg2  1  0.0  0.0  0.38  1.0
  Mg  Mg3  1  0.38  0.0  0.0  1.0
  Re  Re0  1  0.38  0.38  0.38  1.0
  Rh  Rh4  1  0.0  0.0  0.0  1.0

data_Mg3ReRh
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.73
_cell_length_b   6.73
_cell_length_c   8.24
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Mg3ReRh
_chemical_formula_sum   'Mg9 Re3 Rh3'
_cell_volume   323.32
_cell_formula_units_Z   3
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  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+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  0.21  0.41  0.79  1.0
  Re  Re1  3  0.0  0.0  0.38  1.0
  Rh  Rh2  3  0.0  0.0  0.0  1.0

Mg Mg Mg Re Rh
Mg3ReRh is Pb (Zr_0.50 Ti_0.48) O_3 structured and crystallizes in the trigonal R3m space group. Mg(1) is bonded in a distorted single-bond geometry to three equivalent Re(1) and one Rh(1) atom. There is one shorter (2.55 Å) and two longer (3.46 Å) Mg(1)-Re(1) bond lengths. The Mg(1)-Rh(1) bond length is 1.81 Å. Re(1) is bonded in a 9-coordinate geometry to nine equivalent Mg(1) atoms. Rh(1) is bonded in a distorted octahedral geometry to three equivalent Mg(1) atoms.