data_SrMgGaHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.2
_cell_length_b   5.2
_cell_length_c   5.2
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrMgGaHg
_chemical_formula_sum   'Sr1 Mg1 Ga1 Hg1'
_cell_volume   99.49
_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  0.52  0.52  0.52  1.0
  Mg  Mg2  1  0.0  0.0  0.0  1.0
  Ga  Ga0  1  0.68  0.68  0.68  1.0
  Hg  Hg1  1  0.84  0.84  0.84  1.0

data_SrMgGaHg
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.2
_cell_length_b   5.2
_cell_length_c   12.74
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SrMgGaHg
_chemical_formula_sum   'Sr3 Mg3 Ga3 Hg3'
_cell_volume   298.48
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  3  0.0  0.0  0.48  1.0
  Mg  Mg1  3  0.0  0.0  0.0  1.0
  Ga  Ga2  3  0.0  0.0  0.32  1.0
  Hg  Hg3  3  0.0  0.0  0.16  1.0

Sr Mg Ga Hg
Sr Mg Ga Hg 0 2 o o o 1 3 - - - 2 3 o o o 
SrMgHgGa crystallizes in the trigonal R3m space group. Sr(1) is bonded to three equivalent Hg(1) and one Ga(1) atom to form distorted SrGaHg3 trigonal pyramids that share  a cornercorner with one Hg(1)Sr3MgGa trigonal bipyramid and corners with six equivalent Sr(1)GaHg3 trigonal pyramids. All Sr(1)-Hg(1) bond lengths are 3.01 Å. The Sr(1)-Ga(1) bond length is 2.05 Å. Mg(1) is bonded in a distorted single-bond geometry to one Hg(1) atom. The Mg(1)-Hg(1) bond length is 2.05 Å. Hg(1) is bonded to three equivalent Sr(1), one Mg(1), and one Ga(1) atom to form HgSr3MgGa trigonal bipyramids that share corners with six equivalent Hg(1)Sr3MgGa trigonal bipyramids and  a cornercorner with one Sr(1)GaHg3 trigonal pyramid. The Hg(1)-Ga(1) bond length is 2.05 Å. Ga(1) is bonded in a 2-coordinate geometry to one Sr(1) and one Hg(1) atom.