data_SrCaHg2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.91
_cell_length_b   3.91
_cell_length_c   7.83
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrCaHg2
_chemical_formula_sum   'Sr1 Ca1 Hg2'
_cell_volume   119.61
_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
  Sr  Sr3  1  0.0  0.0  0.92  1.0
  Ca  Ca0  1  0.0  0.0  0.0  1.0
  Hg  Hg1  1  0.95  0.95  0.83  1.0
  Hg  Hg2  1  0.95  0.95  0.0  1.0

data_SrCaHg2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.53
_cell_length_b   5.53
_cell_length_c   7.83
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   SrCaHg2
_chemical_formula_sum   'Sr2 Ca2 Hg4'
_cell_volume   239.21
_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
  Sr  Sr0  2  0.0  0.0  0.92  1.0
  Ca  Ca1  2  0.0  0.0  0.0  1.0
  Hg  Hg2  2  0.45  0.5  0.0  1.0
  Hg  Hg3  2  0.45  0.5  0.83  1.0

Sr Ca Hg Hg
SrCaHg2 crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two SrCaHg2 clusters. Sr(1) is bonded in a 3-coordinate geometry to one Ca(1), one Hg(1), and one Hg(2) atom. The Sr(1)-Ca(1) bond length is 0.65 Å. The Sr(1)-Hg(1) bond length is 0.72 Å. The Sr(1)-Hg(2) bond length is 0.72 Å. Ca(1) is bonded in a distorted L-shaped geometry to one Sr(1) and one Hg(2) atom. The Ca(1)-Hg(2) bond length is 0.26 Å. There are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a single-bond geometry to one Sr(1) atom. In the second Hg site, Hg(2) is bonded in a 2-coordinate geometry to one Sr(1) and one Ca(1) atom.