data_AlB2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.22
_cell_length_b   3.22
_cell_length_c   4.9
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   AlB2Se
_chemical_formula_sum   'Al1 B2 Se1'
_cell_volume   50.87
_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  0.31  1.0
  B  B1  1  0.61  0.61  0.47  1.0
  B  B2  1  0.0  0.0  0.8  1.0
  Se  Se3  1  0.61  0.61  0.66  1.0

data_AlB2Se
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.56
_cell_length_b   4.56
_cell_length_c   4.9
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   AlB2Se
_chemical_formula_sum   'Al2 B4 Se2'
_cell_volume   101.75
_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
  Al  Al0  2  0.0  0.0  0.31  1.0
  B  B1  2  0.0  0.0  0.8  1.0
  B  B2  2  0.11  0.5  0.47  1.0
  Se  Se3  2  0.11  0.5  0.66  1.0

Al B B Se
AlB2Se crystallizes in the monoclinic Cm space group. Al(1) is bonded in a 5-coordinate geometry to two equivalent B(2) and three equivalent B(1) atoms. There is one shorter (2.41 Å) and one longer (2.49 Å) Al(1)-B(2) bond length. There is one shorter (1.94 Å) and two longer (2.47 Å) Al(1)-B(1) bond lengths. There are two inequivalent B sites. In the first B site, B(1) is bonded in a distorted single-bond geometry to three equivalent Al(1) and one Se(1) atom. The B(1)-Se(1) bond length is 0.92 Å. In the second B site, B(2) is bonded in a 5-coordinate geometry to two equivalent Al(1) and three equivalent Se(1) atoms. There is one shorter (1.90 Å) and two longer (2.44 Å) B(2)-Se(1) bond lengths. Se(1) is bonded in a distorted single-bond geometry to one B(1) and three equivalent B(2) atoms.