data_KCu2As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.95
_cell_length_b   5.95
_cell_length_c   5.95
_cell_angle_alpha   151.79
_cell_angle_beta   124.75
_cell_angle_gamma   63.18
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KCu2As
_chemical_formula_sum   'K1 Cu2 As1'
_cell_volume   81.07
_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  0.95  1.0
  Cu  Cu1  1  0.0  0.0  0.05  1.0
  Cu  Cu2  1  0.0  0.76  0.13  1.0
  As  As0  1  0.45  0.0  1.0  1.0

data_KCu2As
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.9
_cell_length_b   5.52
_cell_length_c   5.95
_cell_angle_alpha   117.63
_cell_angle_beta   104.1
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KCu2As
_chemical_formula_sum   'K1 Cu2 As1'
_cell_volume   81.07
_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  K0  1  0.05  0.05  0.05  1.0
  Cu  Cu1  1  0.87  0.63  0.63  1.0
  Cu  Cu2  1  0.95  0.95  0.95  1.0
  As  As3  1  0.45  0.0  0.45  1.0

K Cu Cu As
KCu2As crystallizes in the triclinic P1 space group. K(1) is bonded in a single-bond geometry to one Cu(1), two equivalent Cu(2), and one As(1) atom. The K(1)-Cu(1) bond length is 0.59 Å. There is one shorter (3.62 Å) and one longer (3.69 Å) K(1)-Cu(2) bond length. The K(1)-As(1) bond length is 2.55 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a single-bond geometry to one K(1) and one Cu(2) atom. The Cu(1)-Cu(2) bond length is 1.86 Å. In the second Cu site, Cu(2) is bonded in a 7-coordinate geometry to two equivalent K(1), one Cu(1), two equivalent Cu(2), and two equivalent As(1) atoms. Both Cu(2)-Cu(2) bond lengths are 2.90 Å. There is one shorter (2.87 Å) and one longer (3.22 Å) Cu(2)-As(1) bond length. As(1) is bonded in a distorted single-bond geometry to one K(1) and two equivalent Cu(2) atoms.