The material described by HfAs2 is Cotunnite structured and crystallizes in the orthorhombic Pnma space group. Hf(1) is bonded in a 9-coordinate geometry to four equivalent As(2) and five equivalent As(1) atoms. There are two inequivalent As sites. In the first As site, As(2) is bonded in a 8-coordinate geometry to four equivalent Hf(1), two equivalent As(1), and two equivalent As(2) atoms. In the second As site, As(1) is bonded in a 5-coordinate geometry to five equivalent Hf(1) and two equivalent As(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_HfAs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.688
_cell_length_b   6.795
_cell_length_c   8.960
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   224.552
_cell_formula_units_Z   4
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  0.250  0.273  0.662  1.0
  Hf  Hf1  1  0.750  0.727  0.338  1.0
  Hf  Hf2  1  0.250  0.773  0.838  1.0
  Hf  Hf3  1  0.750  0.227  0.162  1.0
  As  As4  1  0.250  0.418  0.352  1.0
  As  As5  1  0.750  0.582  0.648  1.0
  As  As6  1  0.250  0.918  0.148  1.0
  As  As7  1  0.750  0.082  0.852  1.0
  As  As8  1  0.750  0.118  0.458  1.0
  As  As9  1  0.250  0.882  0.542  1.0
  As  As10  1  0.750  0.618  0.042  1.0
  As  As11  1  0.250  0.382  0.958  1.0
[/CIF]
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The material described by HfAs2 is Cotunnite structured and crystallizes in the orthorhombic Pnma space group. Hf(1) is bonded in a 9-coordinate geometry to four equivalent As(2) and five equivalent As(1) atoms. There are two inequivalent As sites. In the first As site, As(2) is bonded in a 8-coordinate geometry to four equivalent Hf(1), two equivalent As(1), and two equivalent As(2) atoms. In the second As site, As(1) is bonded in a 5-coordinate geometry to five equivalent Hf(1) and two equivalent As(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_HfAs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.688
_cell_length_b   6.795
_cell_length_c   8.960
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   224.552
_cell_formula_units_Z   4
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  0.250  0.273  0.662  1.0
  Hf  Hf1  1  0.750  0.727  0.338  1.0
  Hf  Hf2  1  0.250  0.773  0.838  1.0
  Hf  Hf3  1  0.750  0.227  0.162  1.0
  As  As4  1  0.250  0.418  0.352  1.0
  As  As5  1  0.750  0.582  0.648  1.0
  As  As6  1  0.250  0.918  0.148  1.0
  As  As7  1  0.750  0.082  0.852  1.0
  As  As8  1  0.750  0.118  0.458  1.0
  As  As9  1  0.250  0.882  0.542  1.0
  As  As10  1  0.750  0.618  0.042  1.0
  As  As11  1  0.250  0.382  0.958  1.0
[/CIF]
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