data_Hf2ZrTa
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.04
_cell_length_b   3.04
_cell_length_c   9.43
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Hf2ZrTa
_chemical_formula_sum   'Hf2 Zr1 Ta1'
_cell_volume   87.04
_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
  Hf  Hf0  1  0.52  0.52  0.16  1.0
  Hf  Hf1  1  0.0  0.0  0.43  1.0
  Zr  Zr3  1  0.0  0.0  0.89  1.0
  Ta  Ta2  1  0.52  0.52  0.65  1.0

data_Hf2ZrTa
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.3
_cell_length_b   4.3
_cell_length_c   9.43
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Hf2ZrTa
_chemical_formula_sum   'Hf4 Zr2 Ta2'
_cell_volume   174.09
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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
  Hf  Hf0  2  0.0  0.0  0.43  1.0
  Hf  Hf1  2  0.02  0.5  0.16  1.0
  Zr  Zr2  2  0.0  0.0  0.89  1.0
  Ta  Ta3  2  0.02  0.5  0.65  1.0

Hf Hf Zr Ta
Hf2ZrTa is beta Cu3Ti-derived structured and crystallizes in the monoclinic Cm space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to four equivalent Hf(1), four equivalent Hf(2), and four equivalent Zr(1) atoms to form HfHf8Zr4 cuboctahedra that share corners with four equivalent Hf(1)Hf8Zr4 cuboctahedra, corners with eight equivalent Ta(1)Hf4Zr4Ta4 cuboctahedra, edges with eight equivalent Zr(1)Hf4Zr4Ta4 cuboctahedra, edges with eight equivalent Ta(1)Hf4Zr4Ta4 cuboctahedra, faces with two equivalent Ta(1)Hf4Zr4Ta4 cuboctahedra, faces with four equivalent Zr(1)Hf4Zr4Ta4 cuboctahedra, and faces with eight equivalent Hf(1)Hf8Zr4 cuboctahedra. All Hf(1)-Hf(1) bond lengths are 3.04 Å. There are a spread of Hf(1)-Hf(2) bond distances ranging from 3.31-3.41 Å. There are a spread of Hf(1)-Zr(1) bond distances ranging from 3.25-3.36 Å. In the second Hf site, Hf(2) is bonded in a 12-coordinate geometry to four equivalent Hf(1), four equivalent Hf(2), and four equivalent Ta(1) atoms. All Hf(2)-Hf(2) bond lengths are 3.04 Å. There are a spread of Hf(2)-Ta(1) bond distances ranging from 2.89-3.01 Å. Zr(1) is bonded to four equivalent Hf(1), four equivalent Zr(1), and four equivalent Ta(1) atoms to form ZrHf4Zr4Ta4 cuboctahedra that share corners with four equivalent Zr(1)Hf4Zr4Ta4 cuboctahedra, edges with eight equivalent Hf(1)Hf8Zr4 cuboctahedra, edges with eight equivalent Ta(1)Hf4Zr4Ta4 cuboctahedra, faces with four equivalent Hf(1)Hf8Zr4 cuboctahedra, faces with four equivalent Ta(1)Hf4Zr4Ta4 cuboctahedra, and faces with eight equivalent Zr(1)Hf4Zr4Ta4 cuboctahedra. All Zr(1)-Zr(1) bond lengths are 3.04 Å. There are a spread of Zr(1)-Ta(1) bond distances ranging from 3.10-3.21 Å. Ta(1) is bonded to four equivalent Hf(2), four equivalent Zr(1), and four equivalent Ta(1) atoms to form distorted TaHf4Zr4Ta4 cuboctahedra that share corners with four equivalent Ta(1)Hf4Zr4Ta4 cuboctahedra, corners with eight equivalent Hf(1)Hf8Zr4 cuboctahedra, edges with eight equivalent Hf(1)Hf8Zr4 cuboctahedra, edges with eight equivalent Zr(1)Hf4Zr4Ta4 cuboctahedra, faces with two equivalent Hf(1)Hf8Zr4 cuboctahedra, faces with four equivalent Zr(1)Hf4Zr4Ta4 cuboctahedra, and faces with eight equivalent Ta(1)Hf4Zr4Ta4 cuboctahedra. All Ta(1)-Ta(1) bond lengths are 3.04 Å.