data_Na2NbHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.12
_cell_length_b   5.12
_cell_length_c   5.12
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2NbHg
_chemical_formula_sum   'Na2 Nb1 Hg1'
_cell_volume   95.02
_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
  Na  Na1  1  0.43  0.43  0.43  1.0
  Na  Na2  1  0.0  0.0  0.0  1.0
  Nb  Nb3  1  0.62  0.62  0.62  1.0
  Hg  Hg0  1  0.81  0.81  0.81  1.0

data_Na2NbHg
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.12
_cell_length_b   5.12
_cell_length_c   12.55
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Na2NbHg
_chemical_formula_sum   'Na6 Nb3 Hg3'
_cell_volume   285.05
_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
  Na  Na0  3  0.0  0.0  0.0  1.0
  Na  Na1  3  0.0  0.0  0.57  1.0
  Nb  Nb2  3  0.0  0.0  0.38  1.0
  Hg  Hg3  3  0.0  0.0  0.19  1.0

Na Na Nb Hg
Na2NbHg crystallizes in the trigonal R3m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to one Nb(1) and three equivalent Hg(1) atoms. The Na(1)-Nb(1) bond length is 2.37 Å. All Na(1)-Hg(1) bond lengths are 3.01 Å. In the second Na site, Na(2) is bonded in a distorted single-bond geometry to three equivalent Nb(1) and one Hg(1) atom. All Na(2)-Nb(1) bond lengths are 3.01 Å. The Na(2)-Hg(1) bond length is 2.37 Å. Nb(1) is bonded in a 5-coordinate geometry to one Na(1), three equivalent Na(2), and one Hg(1) atom. The Nb(1)-Hg(1) bond length is 2.37 Å. Hg(1) is bonded in a 5-coordinate geometry to one Na(2), three equivalent Na(1), and one Nb(1) atom.