data_PmNi2Hg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.65
_cell_length_b   4.65
_cell_length_c   4.65
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   PmNi2Hg
_chemical_formula_sum   'Pm1 Ni2 Hg1'
_cell_volume   71.03
_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
  Pm  Pm3  1  0.0  0.0  0.0  1.0
  Ni  Ni1  1  0.64  0.64  0.64  1.0
  Ni  Ni2  1  0.93  0.93  0.93  1.0
  Hg  Hg0  1  0.29  0.29  0.29  1.0

data_PmNi2Hg
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.65
_cell_length_b   4.65
_cell_length_c   11.39
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   PmNi2Hg
_chemical_formula_sum   'Pm3 Ni6 Hg3'
_cell_volume   213.08
_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
  Pm  Pm0  3  0.0  0.0  0.0  1.0
  Ni  Ni1  3  0.0  0.0  0.07  1.0
  Ni  Ni2  3  0.0  0.0  0.36  1.0
  Hg  Hg3  3  0.0  0.0  0.71  1.0

Pm Ni Ni Hg
PmNi2Hg crystallizes in the trigonal R3m space group. Pm(1) is bonded in a single-bond geometry to one Ni(2), three equivalent Ni(1), and four equivalent Hg(1) atoms. The Pm(1)-Ni(2) bond length is 0.79 Å. All Pm(1)-Ni(1) bond lengths are 2.70 Å. There are three shorter (2.74 Å) and one longer (3.27 Å) Pm(1)-Hg(1) bond length. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a distorted hexagonal planar geometry to three equivalent Pm(1) and three equivalent Hg(1) atoms. All Ni(1)-Hg(1) bond lengths are 2.70 Å. In the second Ni site, Ni(2) is bonded in a single-bond geometry to one Pm(1) and three equivalent Hg(1) atoms. All Ni(2)-Hg(1) bond lengths are 2.70 Å. Hg(1) is bonded in a 10-coordinate geometry to four equivalent Pm(1), three equivalent Ni(1), and three equivalent Ni(2) atoms.