data_PmNbHg2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.04
_cell_length_b   5.04
_cell_length_c   5.04
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   PmNbHg2
_chemical_formula_sum   'Pm1 Nb1 Hg2'
_cell_volume   90.3
_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  0.56  0.56  0.56  1.0
  Nb  Nb2  1  0.0  0.0  0.0  1.0
  Hg  Hg0  1  0.34  0.34  0.34  1.0
  Hg  Hg1  1  0.78  0.78  0.78  1.0

data_PmNbHg2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.04
_cell_length_b   5.04
_cell_length_c   12.34
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   PmNbHg2
_chemical_formula_sum   'Pm3 Nb3 Hg6'
_cell_volume   270.9
_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  0.44  1.0
  Nb  Nb1  3  0.0  0.0  -0.0  1.0
  Hg  Hg2  3  0.0  0.0  0.22  1.0
  Hg  Hg3  3  0.0  0.0  0.66  1.0

Pm Nb Hg Hg
Pm Nb Hg Hg 0 2 o o o 0 2 o o + 0 2 + o o 0 2 o + o 0 3 o - o 0 3 - o o 0 3 o o - 0 3 o o o 0 1 o + + 0 1 + o + 0 1 + + o 1 3 - - - 1 3 - - o 1 3 o - - 1 3 - o - 1 2 - o o 1 2 o - o 1 2 o o - 2 3 - o o 2 3 o - o 2 3 o o - 
PmNbHg2 is Heusler structured and crystallizes in the trigonal R3m space group. Pm(1) is bonded in a 11-coordinate geometry to three equivalent Nb(1), four equivalent Hg(1), and four equivalent Hg(2) atoms. All Pm(1)-Nb(1) bond lengths are 3.19 Å. There is one shorter (2.71 Å) and three longer (3.23 Å) Pm(1)-Hg(1) bond lengths. There is one shorter (2.71 Å) and three longer (3.23 Å) Pm(1)-Hg(2) bond lengths. Nb(1) is bonded in a 10-coordinate geometry to three equivalent Pm(1), three equivalent Hg(1), and four equivalent Hg(2) atoms. All Nb(1)-Hg(1) bond lengths are 2.91 Å. There is one shorter (2.71 Å) and three longer (3.23 Å) Nb(1)-Hg(2) bond lengths. There are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a 7-coordinate geometry to four equivalent Pm(1) and three equivalent Nb(1) atoms. In the second Hg site, Hg(2) is bonded in a 2-coordinate geometry to four equivalent Pm(1) and four equivalent Nb(1) atoms.