data_FeRh
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.81
_cell_length_b   4.81
_cell_length_c   4.81
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeRh
_chemical_formula_sum   'Fe4 Rh4'
_cell_volume   111.22
_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
  Fe  Fe0  1  0.94  0.94  0.94  1.0
  Fe  Fe1  1  0.46  0.87  0.34  1.0
  Fe  Fe2  1  0.87  0.34  0.46  1.0
  Fe  Fe3  1  0.34  0.46  0.87  1.0
  Rh  Rh4  1  0.47  0.47  0.47  1.0
  Rh  Rh5  1  0.93  0.34  0.87  1.0
  Rh  Rh6  1  0.34  0.87  0.93  1.0
  Rh  Rh7  1  0.87  0.93  0.34  1.0

data_FeRh
_symmetry_space_group_name_H-M   R3
_cell_length_a   6.8
_cell_length_b   6.8
_cell_length_c   8.33
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   146
_chemical_formula_structural   FeRh
_chemical_formula_sum   'Fe12 Rh12'
_cell_volume   333.66
_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
  Fe  Fe0  9  0.12  0.36  0.23  1.0
  Fe  Fe1  3  0.0  0.0  0.94  1.0
  Rh  Rh2  9  0.16  0.38  0.72  1.0
  Rh  Rh3  3  0.0  0.0  0.47  1.0

Fe Fe Fe Fe Rh Rh Rh Rh
FeRh is alpha As-derived structured and crystallizes in the trigonal R3 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 3-coordinate geometry to three equivalent Rh(2) atoms. All Fe(1)-Rh(2) bond lengths are 1.95 Å. In the second Fe site, Fe(2) is bonded in a distorted trigonal non-coplanar geometry to one Rh(1) and two equivalent Rh(2) atoms. The Fe(2)-Rh(1) bond length is 2.01 Å. There is one shorter (2.00 Å) and one longer (2.06 Å) Fe(2)-Rh(2) bond length. There are two inequivalent Rh sites. In the first Rh site, Rh(1) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Fe(2) atoms. In the second Rh site, Rh(2) is bonded in a 3-coordinate geometry to one Fe(1) and two equivalent Fe(2) atoms.