data_KCa4Al
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.09
_cell_length_b   7.09
_cell_length_c   7.09
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KCa4Al
_chemical_formula_sum   'K1 Ca4 Al1'
_cell_volume   251.57
_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
  K  K5  1  0.52  0.52  0.52  1.0
  Ca  Ca1  1  0.27  0.27  0.75  1.0
  Ca  Ca2  1  0.27  0.75  0.27  1.0
  Ca  Ca3  1  0.75  0.27  0.27  1.0
  Ca  Ca4  1  0.75  0.75  0.75  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0

data_KCa4Al
_symmetry_space_group_name_H-M   R3m
_cell_length_a   7.09
_cell_length_b   7.09
_cell_length_c   17.36
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   KCa4Al
_chemical_formula_sum   'K3 Ca12 Al3'
_cell_volume   754.71
_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
  K  K0  3  0.0  0.0  0.48  1.0
  Ca  Ca1  9  0.02  0.51  0.23  1.0
  Ca  Ca2  3  0.0  0.0  0.25  1.0
  Al  Al3  3  0.0  0.0  0.0  1.0

K Ca Ca Ca Ca Al
KCa4Al crystallizes in the trigonal R3m space group. K(1) is bonded in a distorted rectangular see-saw-like geometry to one Ca(2) and three equivalent Ca(1) atoms. The K(1)-Ca(2) bond length is 4.00 Å. All K(1)-Ca(1) bond lengths are 2.42 Å. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a linear geometry to one K(1), two equivalent Ca(2), and one Al(1) atom. Both Ca(1)-Ca(2) bond lengths are 3.56 Å. The Ca(1)-Al(1) bond length is 2.76 Å. In the second Ca site, Ca(2) is bonded to one K(1) and six equivalent Ca(1) atoms to form corner-sharing CaKCa6 hexagonal pyramids. Al(1) is bonded in a distorted T-shaped geometry to three equivalent Ca(1) atoms.