data_KGeAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.05
_cell_length_b   5.05
_cell_length_c   5.05
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KGeAs
_chemical_formula_sum   'K1 Ge1 As1'
_cell_volume   90.8
_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  0.0  0.0  0.0  1.0
  Ge  Ge1  1  0.57  0.57  0.57  1.0
  As  As0  1  0.35  0.35  0.35  1.0

data_KGeAs
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.05
_cell_length_b   5.05
_cell_length_c   12.36
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   KGeAs
_chemical_formula_sum   'K3 Ge3 As3'
_cell_volume   272.41
_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
  Ge  Ge1  3  0.0  0.0  0.43  1.0
  As  As2  3  0.0  0.0  0.65  1.0

K Ge As
KGeAs is half-Heusler structured and crystallizes in the trigonal R3m space group. K(1) is bonded in a hexagonal planar geometry to three equivalent Ge(1) and three equivalent As(1) atoms. All K(1)-Ge(1) bond lengths are 3.16 Å. All K(1)-As(1) bond lengths are 2.92 Å. Ge(1) is bonded to three equivalent K(1) and one As(1) atom to form GeK3As tetrahedra that share corners with six equivalent Ge(1)K3As tetrahedra, corners with three equivalent As(1)K3Ge trigonal pyramids, and edges with three equivalent As(1)K3Ge trigonal pyramids. The Ge(1)-As(1) bond length is 2.67 Å. As(1) is bonded to three equivalent K(1) and one Ge(1) atom to form AsK3Ge trigonal pyramids that share corners with three equivalent Ge(1)K3As tetrahedra, corners with six equivalent As(1)K3Ge trigonal pyramids, and edges with three equivalent Ge(1)K3As tetrahedra.