data_BeHg2Cl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.06
_cell_length_b   5.06
_cell_length_c   5.06
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BeHg2Cl
_chemical_formula_sum   'Be1 Hg2 Cl1'
_cell_volume   91.78
_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
  Be  Be0  1  0.0  0.0  0.0  1.0
  Hg  Hg2  1  0.79  0.79  0.79  1.0
  Hg  Hg3  1  0.37  0.37  0.37  1.0
  Cl  Cl1  1  0.58  0.58  0.58  1.0

data_BeHg2Cl
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.06
_cell_length_b   5.06
_cell_length_c   12.4
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   BeHg2Cl
_chemical_formula_sum   'Be3 Hg6 Cl3'
_cell_volume   275.34
_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
  Be  Be0  3  0.0  0.0  0.0  1.0
  Hg  Hg1  3  0.0  0.0  0.21  1.0
  Hg  Hg2  3  0.0  0.0  0.63  1.0
  Cl  Cl3  3  0.0  0.0  0.42  1.0

Be Hg Hg Cl
BeHg2Cl is Heusler structured and crystallizes in the trigonal R3m space group. Be(1) is bonded to one Hg(1) and three equivalent Hg(2) atoms to form distorted corner-sharing BeHg4 trigonal pyramids. The Be(1)-Hg(1) bond length is 2.60 Å. All Be(1)-Hg(2) bond lengths are 2.96 Å. There are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a linear geometry to one Be(1) and one Cl(1) atom. The Hg(1)-Cl(1) bond length is 2.60 Å. In the second Hg site, Hg(2) is bonded in a distorted single-bond geometry to three equivalent Be(1) and one Cl(1) atom. The Hg(2)-Cl(1) bond length is 2.60 Å. Cl(1) is bonded in a linear geometry to one Hg(1) and one Hg(2) atom.