data_KSnAs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.24
_cell_length_b   5.24
_cell_length_c   5.24
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KSnAs2
_chemical_formula_sum   'K1 Sn1 As2'
_cell_volume   101.88
_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
  Sn  Sn3  1  0.85  0.85  0.85  1.0
  As  As0  1  0.71  0.71  0.71  1.0
  As  As1  1  0.56  0.56  0.56  1.0

data_KSnAs2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.24
_cell_length_b   5.24
_cell_length_c   12.84
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   KSnAs2
_chemical_formula_sum   'K3 Sn3 As6'
_cell_volume   305.65
_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
  Sn  Sn1  3  0.0  0.0  0.15  1.0
  As  As2  3  0.0  0.0  0.29  1.0
  As  As3  3  0.0  0.0  0.44  1.0

K Sn As As
K Sn As As 0 1 - - - 1 2 o o o 2 3 o o o 
KSnAs2 crystallizes in the trigonal R3m space group. K(1) is bonded in a distorted single-bond geometry to one Sn(1), three equivalent As(1), and three equivalent As(2) atoms. The K(1)-Sn(1) bond length is 1.88 Å. All K(1)-As(1) bond lengths are 3.07 Å. All K(1)-As(2) bond lengths are 3.32 Å. Sn(1) is bonded in a distorted linear geometry to one K(1), one As(1), and three equivalent As(2) atoms. The Sn(1)-As(1) bond length is 1.88 Å. All Sn(1)-As(2) bond lengths are 3.07 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded to three equivalent K(1), one Sn(1), and one As(2) atom to form distorted corner-sharing AsK3SnAs trigonal bipyramids. The As(1)-As(2) bond length is 1.88 Å. In the second As site, As(2) is bonded in a 7-coordinate geometry to three equivalent K(1), three equivalent Sn(1), and one As(1) atom.