data_TaAs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.88
_cell_length_b   7.88
_cell_length_c   7.88
_cell_angle_alpha   158.75
_cell_angle_beta   158.75
_cell_angle_gamma   30.23
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TaAs2
_chemical_formula_sum   'Ta1 As2'
_cell_volume   64.34
_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
  Ta  Ta2  1  0.0  0.0  0.0  1.0
  As  As0  1  0.0  0.0  0.63  1.0
  As  As1  1  0.0  0.0  0.59  1.0

data_TaAs2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.11
_cell_length_b   4.11
_cell_length_c   7.88
_cell_angle_alpha   90.0
_cell_angle_beta   105.12
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   TaAs2
_chemical_formula_sum   'Ta2 As4'
_cell_volume   128.68
_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
  Ta  Ta0  2  0.0  0.0  0.0  1.0
  As  As1  2  0.0  0.0  0.37  1.0
  As  As2  2  0.0  0.0  0.41  1.0

Ta As As
Ta As As 0 0 + o + 0 0 o + + 0 2 o o - 0 1 o o - 1 2 o o o 
TaAs2 crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two TaAs2 clusters. Ta(1) is bonded in a distorted single-bond geometry to one As(1) atom. The Ta(1)-As(1) bond length is 2.90 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded in a single-bond geometry to one Ta(1) and one As(2) atom. The As(1)-As(2) bond length is 0.34 Å. In the second As site, As(2) is bonded in a single-bond geometry to one As(1) atom.