data_GaCuNi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.94
_cell_length_b   3.94
_cell_length_c   3.94
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   GaCuNi
_chemical_formula_sum   'Ga1 Cu1 Ni1'
_cell_volume   43.12
_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
  Ga  Ga1  1  0.17  0.17  0.17  1.0
  Cu  Cu0  1  0.78  0.78  0.78  1.0
  Ni  Ni2  1  0.0  0.0  0.0  1.0

data_GaCuNi
_symmetry_space_group_name_H-M   R3m
_cell_length_a   3.94
_cell_length_b   3.94
_cell_length_c   9.64
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   GaCuNi
_chemical_formula_sum   'Ga3 Cu3 Ni3'
_cell_volume   129.35
_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
  Ga  Ga0  3  0.0  0.0  0.83  1.0
  Cu  Cu1  3  0.0  0.0  0.22  1.0
  Ni  Ni2  3  0.0  0.0  0.0  1.0

Ga Cu Ni
Ga Cu Ni 0 2 o o o 0 1 o - - 0 1 - o - 0 1 - - o 1 2 + o + 1 2 o + + 1 2 + + o 1 2 + + + 
NiCuGa is half-Heusler structured and crystallizes in the trigonal R3m space group. Ni(1) is bonded in a 1-coordinate geometry to four equivalent Cu(1) and one Ga(1) atom. There is one shorter (2.09 Å) and three longer (2.53 Å) Ni(1)-Cu(1) bond lengths. The Ni(1)-Ga(1) bond length is 1.68 Å. Cu(1) is bonded in a 7-coordinate geometry to four equivalent Ni(1) and three equivalent Ga(1) atoms. All Cu(1)-Ga(1) bond lengths are 2.34 Å. Ga(1) is bonded in a distorted single-bond geometry to one Ni(1) and three equivalent Cu(1) atoms.