data_NaBeHg2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.21
_cell_length_b   3.21
_cell_length_c   7.73
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaBeHg2
_chemical_formula_sum   'Na1 Be1 Hg2'
_cell_volume   79.68
_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  Na3  1  0.0  0.0  0.87  1.0
  Be  Be0  1  0.0  0.0  0.0  1.0
  Hg  Hg1  1  0.61  0.61  0.56  1.0
  Hg  Hg2  1  0.61  0.61  0.17  1.0

data_NaBeHg2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.54
_cell_length_b   4.54
_cell_length_c   7.73
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   NaBeHg2
_chemical_formula_sum   'Na2 Be2 Hg4'
_cell_volume   159.36
_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+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  Na0  2  0.0  0.0  0.87  1.0
  Be  Be1  2  0.0  0.0  0.0  1.0
  Hg  Hg2  2  0.11  0.5  0.17  1.0
  Hg  Hg3  2  0.11  0.5  0.56  1.0

Na Be Hg Hg
Na Be Hg Hg 0 1 o o + 0 2 o o o 0 2 o - o 0 2 - o o 0 2 - - o 0 3 - - + 1 3 o - o 1 3 - o o 1 3 - - o 2 2 + o o 2 2 o + o 2 3 o o o 
NaBeHg2 crystallizes in the monoclinic Cm space group. Na(1) is bonded in a single-bond geometry to one Be(1) and four equivalent Hg(1) atoms. The Na(1)-Be(1) bond length is 1.03 Å. There are a spread of Na(1)-Hg(1) bond distances ranging from 2.96-3.62 Å. Be(1) is bonded in a distorted single-bond geometry to one Na(1) and three equivalent Hg(2) atoms. There is one shorter (2.23 Å) and two longer (2.67 Å) Be(1)-Hg(2) bond lengths. There are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a 9-coordinate geometry to four equivalent Na(1), one Hg(2), and four equivalent Hg(1) atoms. The Hg(1)-Hg(2) bond length is 3.02 Å. All Hg(1)-Hg(1) bond lengths are 3.21 Å. In the second Hg site, Hg(2) is bonded in a 3-coordinate geometry to three equivalent Be(1) and one Hg(1) atom.