data_Hf3As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.38
_cell_length_b   3.38
_cell_length_c   8.69
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Hf3As
_chemical_formula_sum   'Hf3 As1'
_cell_volume   86.03
_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  Hf1  1  0.0  0.0  0.35  1.0
  Hf  Hf2  1  0.69  0.98  0.88  1.0
  Hf  Hf3  1  0.69  0.98  0.81  1.0
  As  As0  1  0.0  0.0  0.0  1.0

data_Hf3As
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.38
_cell_length_b   3.38
_cell_length_c   8.69
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Hf3As
_chemical_formula_sum   'Hf3 As1'
_cell_volume   86.03
_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  0.0  0.0  0.35  1.0
  Hf  Hf1  1  0.69  0.98  0.81  1.0
  Hf  Hf2  1  0.69  0.98  0.88  1.0
  As  As3  1  0.0  0.0  0.0  1.0

Hf Hf Hf As
Hf3As crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one Hf3As cluster. There are three inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a single-bond geometry to one As(1) atom. The Hf(1)-As(1) bond length is 3.01 Å. In the second Hf site, Hf(2) is bonded in a 2-coordinate geometry to one Hf(3) and one As(1) atom. The Hf(2)-Hf(3) bond length is 0.62 Å. The Hf(2)-As(1) bond length is 1.44 Å. In the third Hf site, Hf(3) is bonded in a single-bond geometry to one Hf(2) atom. As(1) is bonded in a distorted single-bond geometry to one Hf(1) and one Hf(2) atom.