data_K4BaCu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.92
_cell_length_b   7.92
_cell_length_c   7.92
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   K4BaCu
_chemical_formula_sum   'K4 Ba1 Cu1'
_cell_volume   350.72
_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  K2  1  0.01  0.01  0.19  1.0
  K  K3  1  0.01  0.19  0.01  1.0
  K  K4  1  0.19  0.01  0.01  1.0
  K  K5  1  0.19  0.19  0.19  1.0
  Ba  Ba0  1  0.4  0.4  0.4  1.0
  Cu  Cu1  1  0.0  0.0  0.0  1.0

data_K4BaCu
_symmetry_space_group_name_H-M   R3m
_cell_length_a   7.92
_cell_length_b   7.92
_cell_length_c   19.39
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   K4BaCu
_chemical_formula_sum   'K12 Ba3 Cu3'
_cell_volume   1052.15
_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  9  0.06  0.12  0.93  1.0
  K  K1  3  0.0  0.0  0.81  1.0
  Ba  Ba2  3  0.0  0.0  0.6  1.0
  Cu  Cu3  3  0.0  0.0  0.0  1.0

K K K K Ba Cu
K4BaCu crystallizes in the trigonal R3m space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 3-coordinate geometry to one K(2), two equivalent K(1), two equivalent Ba(1), and one Cu(1) atom. The K(1)-K(2) bond length is 2.45 Å. Both K(1)-K(1) bond lengths are 1.41 Å. Both K(1)-Ba(1) bond lengths are 4.22 Å. The K(1)-Cu(1) bond length is 1.54 Å. In the second K site, K(2) is bonded in a distorted rectangular see-saw-like geometry to three equivalent K(1) and one Ba(1) atom. The K(2)-Ba(1) bond length is 4.06 Å. Ba(1) is bonded to one K(2) and six equivalent K(1) atoms to form distorted corner-sharing BaK7 hexagonal pyramids. Cu(1) is bonded in a 3-coordinate geometry to three equivalent K(1) atoms.