data_NaSiHg2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.67
_cell_length_b   4.67
_cell_length_c   4.01
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaSiHg2
_chemical_formula_sum   'Na1 Si1 Hg2'
_cell_volume   87.48
_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  Na2  1  0.0  0.0  0.0  1.0
  Si  Si3  1  0.33  0.33  0.0  1.0
  Hg  Hg0  1  0.33  0.0  0.01  1.0
  Hg  Hg1  1  0.0  0.33  0.01  1.0

data_NaSiHg2
_symmetry_space_group_name_H-M   Amm2
_cell_length_a   4.01
_cell_length_b   6.6
_cell_length_c   6.6
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   38
_chemical_formula_structural   NaSiHg2
_chemical_formula_sum   'Na2 Si2 Hg4'
_cell_volume   174.96
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-x, -y, z'
  3  '-x, y, z'
  4  'x, -y, z'
  5  'x, y+1/2, z+1/2'
  6  '-x, -y+1/2, z+1/2'
  7  '-x, y+1/2, z+1/2'
  8  'x, -y+1/2, z+1/2'
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  2  0.0  0.0  0.0  1.0
  Si  Si1  2  0.0  0.0  0.33  1.0
  Hg  Hg2  4  0.0  0.17  0.17  1.0

Na Si Hg Hg
NaHg2Si is alpha Po structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two NaHg2Si clusters. Na(1) is bonded in an L-shaped geometry to two equivalent Hg(1) atoms. Both Na(1)-Hg(1) bond lengths are 1.56 Å. Hg(1) is bonded in a 1-coordinate geometry to one Na(1) and one Si(1) atom. The Hg(1)-Si(1) bond length is 1.56 Å. Si(1) is bonded in an L-shaped geometry to two equivalent Hg(1) atoms.