data_CaHgAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.69
_cell_length_b   5.69
_cell_length_c   5.69
_cell_angle_alpha   140.52
_cell_angle_beta   140.52
_cell_angle_gamma   57.06
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaHgAs
_chemical_formula_sum   'Ca1 Hg1 As1'
_cell_volume   73.93
_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
  Ca  Ca1  1  0.0  0.0  0.38  1.0
  Hg  Hg2  1  0.0  0.0  0.57  1.0
  As  As0  1  0.0  0.0  0.05  1.0

data_CaHgAs
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.44
_cell_length_b   5.44
_cell_length_c   5.69
_cell_angle_alpha   90.0
_cell_angle_beta   118.53
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   CaHgAs
_chemical_formula_sum   'Ca2 Hg2 As2'
_cell_volume   147.86
_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
  Ca  Ca0  2  0.0  0.0  0.62  1.0
  Hg  Hg1  2  0.0  0.0  0.43  1.0
  As  As2  2  0.0  0.0  0.95  1.0

Ca Hg As
CaHgAs crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two CaHgAs clusters. Ca(1) is bonded in a linear geometry to one Hg(1) and one As(1) atom. The Ca(1)-Hg(1) bond length is 1.08 Å. The Ca(1)-As(1) bond length is 1.91 Å. Hg(1) is bonded in a single-bond geometry to one Ca(1) atom. As(1) is bonded in a distorted single-bond geometry to one Ca(1) atom.