data_BaMgCuHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.27
_cell_length_b   5.27
_cell_length_c   5.27
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BaMgCuHg
_chemical_formula_sum   'Ba1 Mg1 Cu1 Hg1'
_cell_volume   103.27
_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
  Ba  Ba0  1  0.59  0.59  0.59  1.0
  Mg  Mg3  1  0.0  0.0  0.0  1.0
  Cu  Cu1  1  0.72  0.72  0.72  1.0
  Hg  Hg2  1  0.86  0.86  0.86  1.0

data_BaMgCuHg
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.27
_cell_length_b   5.27
_cell_length_c   12.9
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   BaMgCuHg
_chemical_formula_sum   'Ba3 Mg3 Cu3 Hg3'
_cell_volume   309.8
_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
  Ba  Ba0  3  0.0  0.0  0.41  1.0
  Mg  Mg1  3  0.0  0.0  0.0  1.0
  Cu  Cu2  3  0.0  0.0  0.28  1.0
  Hg  Hg3  3  0.0  0.0  0.14  1.0

Ba Mg Cu Hg
Ba Mg Cu Hg 0 2 o o o 1 3 - - - 2 3 o o o 
BaMgCuHg crystallizes in the trigonal R3m space group. Ba(1) is bonded in a single-bond geometry to one Cu(1) and three equivalent Hg(1) atoms. The Ba(1)-Cu(1) bond length is 1.78 Å. All Ba(1)-Hg(1) bond lengths are 3.13 Å. Mg(1) is bonded in a single-bond geometry to one Hg(1) atom. The Mg(1)-Hg(1) bond length is 1.78 Å. Cu(1) is bonded in a 2-coordinate geometry to one Ba(1) and one Hg(1) atom. The Cu(1)-Hg(1) bond length is 1.78 Å. Hg(1) is bonded in a 5-coordinate geometry to three equivalent Ba(1), one Mg(1), and one Cu(1) atom.