data_GaAs2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.35
_cell_length_b   3.35
_cell_length_c   6.88
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   GaAs2Se
_chemical_formula_sum   'Ga1 As2 Se1'
_cell_volume   77.26
_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
  Ga  Ga2  1  0.0  0.0  0.0  1.0
  As  As0  1  0.68  0.68  0.21  1.0
  As  As1  1  0.68  0.68  0.68  1.0
  Se  Se3  1  0.0  0.0  0.44  1.0

data_GaAs2Se
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.74
_cell_length_b   4.74
_cell_length_c   6.88
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   GaAs2Se
_chemical_formula_sum   'Ga2 As4 Se2'
_cell_volume   154.52
_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
  Ga  Ga0  2  0.0  0.0  0.0  1.0
  As  As1  2  0.18  0.5  0.21  1.0
  As  As2  2  0.18  0.5  0.68  1.0
  Se  Se3  2  0.0  0.0  0.44  1.0

Ga As As Se
GaAs2Se crystallizes in the monoclinic Cm space group. Ga(1) is bonded in a 1-coordinate geometry to one As(1) and one As(2) atom. The Ga(1)-As(1) bond length is 2.09 Å. The Ga(1)-As(2) bond length is 2.70 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded in a distorted L-shaped geometry to one Ga(1) and one Se(1) atom. The As(1)-Se(1) bond length is 2.24 Å. In the second As site, As(2) is bonded in a 4-coordinate geometry to one Ga(1) and three equivalent Se(1) atoms. There is one shorter (2.24 Å) and two longer (2.99 Å) As(2)-Se(1) bond lengths. Se(1) is bonded in a distorted L-shaped geometry to one As(1) and three equivalent As(2) atoms.