data_SrHg3C
_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   SrHg3C
_chemical_formula_sum   'Sr1 Hg3 C1'
_cell_volume   121.9
_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
  Sr  Sr0  1  0.48  0.48  0.48  1.0
  Hg  Hg2  1  0.0  0.48  0.0  1.0
  Hg  Hg3  1  0.0  0.0  0.48  1.0
  Hg  Hg4  1  0.48  0.0  0.0  1.0
  C  C1  1  0.0  0.0  0.0  1.0

data_SrHg3C
_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   SrHg3C
_chemical_formula_sum   'Sr3 Hg9 C3'
_cell_volume   365.71
_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
  Sr  Sr0  3  0.0  0.0  0.48  1.0
  Hg  Hg1  9  0.17  0.35  0.83  1.0
  C  C2  3  0.0  0.0  0.0  1.0

Sr Hg Hg Hg C
SrHg3C is (Cubic) Perovskite structured and crystallizes in the trigonal R3m space group. Sr(1) is bonded to twelve equivalent Hg(1) atoms to form SrHg12 cuboctahedra that share corners with twelve equivalent Sr(1)Hg12 cuboctahedra, faces with six equivalent Sr(1)Hg12 cuboctahedra, and faces with eight equivalent C(1)Hg6 octahedra. There are a spread of Sr(1)-Hg(1) bond distances ranging from 3.36-3.65 Å. Hg(1) is bonded in a 2-coordinate geometry to four equivalent Sr(1) and two equivalent C(1) atoms. There is one shorter (2.38 Å) and one longer (2.58 Å) Hg(1)-C(1) bond length. C(1) is bonded to six equivalent Hg(1) atoms to form CHg6 octahedra that share corners with six equivalent C(1)Hg6 octahedra and faces with eight equivalent Sr(1)Hg12 cuboctahedra. The corner-sharing octahedra are not tilted.