data_MgHg2As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.23
_cell_length_b   4.23
_cell_length_c   4.92
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgHg2As
_chemical_formula_sum   'Mg1 Hg2 As1'
_cell_volume   87.98
_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
  Mg  Mg3  1  0.0  0.0  0.0  1.0
  Hg  Hg1  1  0.11  0.0  0.46  1.0
  Hg  Hg2  1  0.0  0.11  0.46  1.0
  As  As0  1  0.11  0.11  0.0  1.0

data_MgHg2As
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.98
_cell_length_b   5.98
_cell_length_c   4.92
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   MgHg2As
_chemical_formula_sum   'Mg2 Hg4 As2'
_cell_volume   175.96
_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+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
  Mg  Mg0  2  0.0  0.0  0.0  1.0
  Hg  Hg1  4  0.06  0.06  0.46  1.0
  As  As2  2  0.11  0.0  -0.0  1.0

Mg Hg Hg As
MgAs(Hg)2 crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Hg clusters and two MgAs 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 0.69 Å. In each MgAs cluster, Mg(1) is bonded in a single-bond geometry to one As(1) atom. The Mg(1)-As(1) bond length is 0.69 Å. As(1) is bonded in a single-bond geometry to one Mg(1) atom.