data_BaNi2Hg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.05
_cell_length_b   5.05
_cell_length_c   5.05
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BaNi2Hg
_chemical_formula_sum   'Ba1 Ni2 Hg1'
_cell_volume   91.12
_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  0.57  0.57  0.57  1.0
  Ni  Ni2  1  0.0  0.0  0.0  1.0
  Ni  Ni3  1  0.79  0.79  0.79  1.0
  Hg  Hg1  1  0.36  0.36  0.36  1.0

data_BaNi2Hg
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.05
_cell_length_b   5.05
_cell_length_c   12.37
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   BaNi2Hg
_chemical_formula_sum   'Ba3 Ni6 Hg3'
_cell_volume   273.35
_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  0.43  1.0
  Ni  Ni1  3  0.0  0.0  -0.0  1.0
  Ni  Ni2  3  0.0  0.0  0.21  1.0
  Hg  Hg3  3  0.0  0.0  0.64  1.0

Ba Ni Ni Hg
Ba Ni Ni Hg 0 3 o o o 0 3 o o + 0 3 + o o 0 3 o + o 0 2 o - o 0 2 - o o 0 2 o o - 0 2 o o o 0 1 o + + 0 1 + o + 0 1 + + o 1 2 - - - 1 2 - - o 1 2 o - - 1 2 - o - 1 3 - o o 1 3 o - o 1 3 o o - 2 3 o o + 2 3 o + o 2 3 + o o 
BaNi2Hg crystallizes in the trigonal R3m space group. Ba(1) is bonded in a distorted linear geometry to three equivalent Ni(1), four equivalent Ni(2), and four equivalent Hg(1) atoms. All Ba(1)-Ni(1) bond lengths are 3.14 Å. There is one shorter (2.65 Å) and three longer (3.27 Å) Ba(1)-Ni(2) bond lengths. There is one shorter (2.65 Å) and three longer (3.27 Å) Ba(1)-Hg(1) bond lengths. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent Ba(1), one Ni(2), and three equivalent Hg(1) atoms to form distorted edge-sharing NiBa3NiHg3 hexagonal pyramids. The Ni(1)-Ni(2) bond length is 2.65 Å. All Ni(1)-Hg(1) bond lengths are 2.93 Å. In the second Ni site, Ni(2) is bonded in a distorted single-bond geometry to four equivalent Ba(1) and one Ni(1) atom. Hg(1) is bonded in a distorted single-bond geometry to four equivalent Ba(1) and three equivalent Ni(1) atoms.