data_Hg2GeAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.27
_cell_length_b   4.27
_cell_length_c   4.89
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Hg2GeAs
_chemical_formula_sum   'Hg2 Ge1 As1'
_cell_volume   89.09
_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
  Hg  Hg2  1  0.0  0.13  0.44  1.0
  Hg  Hg3  1  0.13  0.0  0.44  1.0
  Ge  Ge1  1  0.0  0.0  0.0  1.0
  As  As0  1  0.13  0.13  0.0  1.0

data_Hg2GeAs
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.04
_cell_length_b   6.04
_cell_length_c   4.89
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Hg2GeAs
_chemical_formula_sum   'Hg4 Ge2 As2'
_cell_volume   178.19
_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
  Hg  Hg0  4  0.07  0.07  0.44  1.0
  Ge  Ge1  2  0.0  0.0  0.0  1.0
  As  As2  2  0.13  0.0  0.0  1.0

Hg Hg Ge As
Hg Hg Ge As 0 1 o o o 2 3 o o o 
(Hg)2GeAs crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two arsanylidynegermanium molecules and two Hg clusters. In each Hg cluster, Hg(1) is bonded in a single-bond geometry to one Hg(1) atom. The Hg(1)-Hg(1) bond length is 0.81 Å.