data_Sr2AlHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.4
_cell_length_b   8.4
_cell_length_c   8.4
_cell_angle_alpha   32.34
_cell_angle_beta   32.34
_cell_angle_gamma   32.34
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sr2AlHg
_chemical_formula_sum   'Sr2 Al1 Hg1'
_cell_volume   150.81
_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  Sr2  1  0.0  0.0  0.84  1.0
  Sr  Sr3  1  0.0  0.0  0.13  1.0
  Al  Al0  1  0.0  0.0  0.9  1.0
  Hg  Hg1  1  0.0  0.0  0.93  1.0

data_Sr2AlHg
_symmetry_space_group_name_H-M   Cm
_cell_length_a   8.1
_cell_length_b   4.68
_cell_length_c   8.4
_cell_angle_alpha   90.0
_cell_angle_beta   108.76
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Sr2AlHg
_chemical_formula_sum   'Sr4 Al2 Hg2'
_cell_volume   301.62
_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  0.16  1.0
  Sr  Sr1  2  0.0  0.0  0.87  1.0
  Al  Al2  2  0.0  0.0  0.1  1.0
  Hg  Hg3  2  0.0  0.0  0.07  1.0

Sr Sr Al Hg
Sr Sr Al Hg 0 2 o o o 1 3 o o - 1 2 o o - 2 3 o o o 
Sr2HgAl is Cyanogen Chloride-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Sr2HgAl clusters. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a single-bond geometry to one Al(1) atom. The Sr(1)-Al(1) bond length is 0.50 Å. In the second Sr site, Sr(2) is bonded in a single-bond geometry to one Hg(1) atom. The Sr(2)-Hg(1) bond length is 1.65 Å. Hg(1) is bonded in a linear geometry to one Sr(2) and one Al(1) atom. The Hg(1)-Al(1) bond length is 0.27 Å. Al(1) is bonded in a linear geometry to one Sr(1) and one Hg(1) atom.