data_CsFe3Hg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.96
_cell_length_b   4.96
_cell_length_c   4.96
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CsFe3Hg
_chemical_formula_sum   'Cs1 Fe3 Hg1'
_cell_volume   121.91
_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
  Cs  Cs0  1  0.0  0.0  0.0  1.0
  Fe  Fe2  1  0.48  0.0  0.48  1.0
  Fe  Fe3  1  0.48  0.48  0.0  1.0
  Fe  Fe4  1  0.0  0.48  0.48  1.0
  Hg  Hg1  1  0.48  0.48  0.48  1.0

data_CsFe3Hg
_symmetry_space_group_name_H-M   R3m
_cell_length_a   7.01
_cell_length_b   7.01
_cell_length_c   8.59
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   CsFe3Hg
_chemical_formula_sum   'Cs3 Fe9 Hg3'
_cell_volume   365.73
_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
  Cs  Cs0  3  0.0  0.0  0.0  1.0
  Fe  Fe1  9  0.01  0.51  0.99  1.0
  Hg  Hg2  3  0.0  0.0  0.48  1.0

Cs Fe Fe Fe Hg
CsFe3Hg is (Cubic) Perovskite structured and crystallizes in the trigonal R3m space group. Cs(1) is bonded to twelve equivalent Fe(1) atoms to form CsFe12 cuboctahedra that share corners with twelve equivalent Cs(1)Fe12 cuboctahedra, faces with six equivalent Cs(1)Fe12 cuboctahedra, and faces with eight equivalent Hg(1)Fe6 octahedra. There are a spread of Cs(1)-Fe(1) bond distances ranging from 3.36-3.65 Å. Fe(1) is bonded to four equivalent Cs(1) and two equivalent Hg(1) atoms to form a mixture of distorted corner, edge, and face-sharing FeCs4Hg2 octahedra. The corner-sharing octahedral tilt angles range from 0-61°. There is one shorter (2.38 Å) and one longer (2.58 Å) Fe(1)-Hg(1) bond length. Hg(1) is bonded to six equivalent Fe(1) atoms to form HgFe6 octahedra that share corners with six equivalent Hg(1)Fe6 octahedra and faces with eight equivalent Cs(1)Fe12 cuboctahedra. The corner-sharing octahedra are not tilted.