data_K2FeSn
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.29
_cell_length_b   5.29
_cell_length_c   5.29
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   K2FeSn
_chemical_formula_sum   'K2 Fe1 Sn1'
_cell_volume   104.52
_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  K1  1  0.0  0.0  0.0  1.0
  K  K2  1  0.87  0.87  0.87  1.0
  Fe  Fe0  1  0.74  0.74  0.74  1.0
  Sn  Sn3  1  0.61  0.61  0.61  1.0

data_K2FeSn
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.29
_cell_length_b   5.29
_cell_length_c   12.95
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   K2FeSn
_chemical_formula_sum   'K6 Fe3 Sn3'
_cell_volume   313.55
_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
  K  K1  3  0.0  0.0  0.13  1.0
  Fe  Fe2  3  0.0  0.0  0.26  1.0
  Sn  Sn3  3  0.0  0.0  0.39  1.0

K K Fe Sn
K K Fe Sn 0 1 - - - 1 2 o o o 2 3 o o o 
K2FeSn crystallizes in the trigonal R3m space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one K(2), three equivalent Fe(1), and three equivalent Sn(1) atoms. The K(1)-K(2) bond length is 1.69 Å. All K(1)-Fe(1) bond lengths are 3.19 Å. All K(1)-Sn(1) bond lengths are 3.15 Å. In the second K site, K(2) is bonded in a distorted single-bond geometry to one K(1) and one Fe(1) atom. The K(2)-Fe(1) bond length is 1.69 Å. Fe(1) is bonded in a distorted linear geometry to one K(2), three equivalent K(1), and one Sn(1) atom. The Fe(1)-Sn(1) bond length is 1.69 Å. Sn(1) is bonded in a distorted single-bond geometry to three equivalent K(1) and one Fe(1) atom.