data_AlAsSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.59
_cell_length_b   4.59
_cell_length_c   4.59
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   AlAsSe
_chemical_formula_sum   'Al1 As1 Se1'
_cell_volume   68.23
_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  0.0  0.0  1.0
  As  As1  1  0.62  0.62  0.62  1.0
  Se  Se2  1  0.24  0.24  0.24  1.0

data_AlAsSe
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.59
_cell_length_b   4.59
_cell_length_c   11.24
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   AlAsSe
_chemical_formula_sum   'Al3 As3 Se3'
_cell_volume   204.7
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  3  0.0  0.0  0.0  1.0
  As  As1  3  0.0  0.0  0.38  1.0
  Se  Se2  3  0.0  0.0  0.76  1.0

Al As Se
Al As Se 0 2 o - o 0 2 - o o 0 2 o o - 0 2 o o o 0 1 - - o 0 1 - o - 0 1 o - - 1 2 o o + 1 2 o + o 1 2 + o o 
AlAsSe is alpha boron-derived structured and crystallizes in the trigonal R3m space group. Al(1) is bonded to three equivalent As(1) and four equivalent Se(1) atoms to form distorted AlAs3Se4 hexagonal pyramids that share corners with three equivalent Se(1)Al4As3 hexagonal pyramids, corners with six equivalent Al(1)As3Se4 hexagonal pyramids, edges with three equivalent Se(1)Al4As3 hexagonal pyramids, and edges with six equivalent Al(1)As3Se4 hexagonal pyramids. All Al(1)-As(1) bond lengths are 2.70 Å. There is one shorter (2.73 Å) and three longer (2.83 Å) Al(1)-Se(1) bond lengths. As(1) is bonded in a hexagonal planar geometry to three equivalent Al(1) and three equivalent Se(1) atoms. All As(1)-Se(1) bond lengths are 2.70 Å. Se(1) is bonded to four equivalent Al(1) and three equivalent As(1) atoms to form distorted SeAl4As3 hexagonal pyramids that share corners with three equivalent Al(1)As3Se4 hexagonal pyramids, corners with six equivalent Se(1)Al4As3 hexagonal pyramids, edges with three equivalent Al(1)As3Se4 hexagonal pyramids, and edges with six equivalent Se(1)Al4As3 hexagonal pyramids.