data_Al3As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.93
_cell_length_b   4.91
_cell_length_c   4.85
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Al3As
_chemical_formula_sum   'Al3 As1'
_cell_volume   69.7
_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
  Al  Al0  1  0.46  0.0  0.84  1.0
  Al  Al1  1  0.0  0.0  0.43  1.0
  Al  Al2  1  0.0  0.45  0.05  1.0
  As  As3  1  0.46  0.45  0.62  1.0

data_Al3As
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.93
_cell_length_b   4.85
_cell_length_c   4.91
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Al3As
_chemical_formula_sum   'Al3 As1'
_cell_volume   69.7
_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
  Al  Al0  1  -0.0  0.95  0.55  1.0
  Al  Al1  1  0.0  0.57  0.0  1.0
  Al  Al2  1  0.54  0.16  0.0  1.0
  As  As3  1  0.54  0.38  0.55  1.0

Al Al Al As
Al Al Al As 0 1 o o o 0 1 + o o 0 2 o o + 0 2 + o + 0 2 + - + 0 2 o - + 0 0 + o o 0 3 o - o 0 3 o o o 1 3 - o o 1 3 o - o 1 3 o o o 1 1 + o o 1 2 o o o 1 2 o - o 2 3 - o - 2 3 - o o 2 3 o o - 2 3 o o o 2 2 + o o 3 3 + o o 
Al3As crystallizes in the triclinic P1 space group. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded in a 1-coordinate geometry to two equivalent Al(2) and two equivalent As(1) atoms. There is one shorter (2.38 Å) and one longer (2.51 Å) Al(1)-Al(2) bond length. There is one shorter (2.47 Å) and one longer (2.88 Å) Al(1)-As(1) bond length. In the second Al site, Al(2) is bonded in a 8-coordinate geometry to one Al(3), two equivalent Al(1), two equivalent Al(2), and three equivalent As(1) atoms. The Al(2)-Al(3) bond length is 2.90 Å. Both Al(2)-Al(2) bond lengths are 2.93 Å. There are a spread of Al(2)-As(1) bond distances ranging from 2.76-3.13 Å. In the third Al site, Al(3) is bonded in a 2-coordinate geometry to one Al(2) and three equivalent As(1) atoms. There are a spread of Al(3)-As(1) bond distances ranging from 2.51-3.06 Å. As(1) is bonded in a 7-coordinate geometry to two equivalent Al(1), three equivalent Al(2), and three equivalent Al(3) atoms.