data_KFe2Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.62
_cell_length_b   4.62
_cell_length_c   6.48
_cell_angle_alpha   100.2
_cell_angle_beta   100.2
_cell_angle_gamma   33.37
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KFe2Si
_chemical_formula_sum   'K1 Fe2 Si1'
_cell_volume   74.67
_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  0.82  0.0  0.19  1.0
  Fe  Fe0  1  0.54  0.0  0.63  1.0
  Fe  Fe1  1  0.11  0.0  0.74  1.0
  Si  Si3  1  0.0  0.0  0.0  1.0

data_KFe2Si
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.65
_cell_length_b   4.62
_cell_length_c   6.48
_cell_angle_alpha   100.2
_cell_angle_beta   90.0
_cell_angle_gamma   106.69
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KFe2Si
_chemical_formula_sum   'K1 Fe2 Si1'
_cell_volume   74.67
_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  0.0  0.18  0.81  1.0
  Fe  Fe1  1  0.0  0.46  0.37  1.0
  Fe  Fe2  1  0.0  0.89  0.26  1.0
  Si  Si3  1  0.0  0.0  0.0  1.0

K Fe Fe Si
K Fe Fe Si 0 3 + o o 1 2 o o o 1 2 + o o 1 1 + - o 1 3 + o + 2 3 o o + 
KFe2Si crystallizes in the triclinic P1 space group. K(1) is bonded in a single-bond geometry to one Fe(1) and one Si(1) atom. The K(1)-Fe(1) bond length is 3.39 Å. The K(1)-Si(1) bond length is 1.58 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 6-coordinate geometry to one K(1), two equivalent Fe(1), two equivalent Fe(2), and one Si(1) atom. Both Fe(1)-Fe(1) bond lengths are 2.65 Å. There is one shorter (2.21 Å) and one longer (2.61 Å) Fe(1)-Fe(2) bond length. The Fe(1)-Si(1) bond length is 2.91 Å. In the second Fe site, Fe(2) is bonded in a 1-coordinate geometry to two equivalent Fe(1) and one Si(1) atom. The Fe(2)-Si(1) bond length is 1.84 Å. Si(1) is bonded in a distorted single-bond geometry to one K(1), one Fe(1), and one Fe(2) atom.