data_KAl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.56
_cell_length_b   5.56
_cell_length_c   9.02
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KAl
_chemical_formula_sum   'K2 Al2'
_cell_volume   241.06
_cell_formula_units_Z   2
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
  K  K2  1  0.78  0.6  0.89  1.0
  K  K3  1  0.0  0.21  0.38  1.0
  Al  Al0  1  0.78  0.6  0.51  1.0
  Al  Al1  1  0.0  0.21  0.0  1.0

data_KAl
_symmetry_space_group_name_H-M   Cm
_cell_length_a   9.62
_cell_length_b   5.56
_cell_length_c   9.02
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   KAl
_chemical_formula_sum   'K4 Al4'
_cell_volume   482.11
_cell_formula_units_Z   4
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
  K  K0  2  0.1  0.5  0.89  1.0
  K  K1  2  0.21  0.0  0.38  1.0
  Al  Al2  2  0.1  0.5  0.51  1.0
  Al  Al3  2  0.21  0.0  -0.0  1.0

K K Al Al
K K Al Al 0 3 + + + 0 3 + o + 0 2 o o o 1 2 - o o 1 2 - - o 1 3 o o o 
AlK is Wurtzite structured and crystallizes in the triclinic P1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to one Al(1) and three equivalent Al(2) atoms to form corner-sharing KAl4 tetrahedra. The K(1)-Al(1) bond length is 3.45 Å. There are a spread of K(1)-Al(2) bond distances ranging from 3.09-3.87 Å. In the second K site, K(2) is bonded to one Al(2) and three equivalent Al(1) atoms to form distorted corner-sharing KAl4 tetrahedra. The K(2)-Al(2) bond length is 3.45 Å. There are a spread of K(2)-Al(1) bond distances ranging from 3.15-3.91 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one K(1) and three equivalent K(2) atoms to form distorted corner-sharing AlK4 tetrahedra. In the second Al site, Al(2) is bonded to one K(2) and three equivalent K(1) atoms to form corner-sharing AlK4 tetrahedra.