data_KCu2Ge
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.73
_cell_length_b   4.73
_cell_length_c   4.73
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KCu2Ge
_chemical_formula_sum   'K1 Cu2 Ge1'
_cell_volume   74.92
_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  K3  1  0.0  0.0  0.0  1.0
  Cu  Cu0  1  0.67  0.67  0.67  1.0
  Cu  Cu1  1  0.02  0.02  0.02  1.0
  Ge  Ge2  1  0.35  0.35  0.35  1.0

data_KCu2Ge
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.73
_cell_length_b   4.73
_cell_length_c   11.59
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   KCu2Ge
_chemical_formula_sum   'K3 Cu6 Ge3'
_cell_volume   224.76
_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  0.0  1.0
  Cu  Cu1  3  0.0  0.0  0.33  1.0
  Cu  Cu2  3  0.0  0.0  0.98  1.0
  Ge  Ge3  3  0.0  0.0  0.65  1.0

K Cu Cu Ge
KCu2Ge crystallizes in the trigonal R3m space group. K(1) is bonded in a single-bond geometry to one Cu(2), four equivalent Cu(1), and three equivalent Ge(1) atoms. The K(1)-Cu(2) bond length is 0.22 Å. There are three shorter (2.73 Å) and one longer (3.79 Å) K(1)-Cu(1) bond length. All K(1)-Ge(1) bond lengths are 2.74 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to four equivalent K(1) and three equivalent Ge(1) atoms to form a mixture of distorted corner and edge-sharing CuK4Ge3 hexagonal pyramids. All Cu(1)-Ge(1) bond lengths are 2.73 Å. In the second Cu site, Cu(2) is bonded in a single-bond geometry to one K(1) and three equivalent Ge(1) atoms. All Cu(2)-Ge(1) bond lengths are 2.73 Å. Ge(1) is bonded in a distorted q6 geometry to three equivalent K(1), three equivalent Cu(1), and three equivalent Cu(2) atoms.