data_ZnFe2Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.99
_cell_length_b   3.99
_cell_length_c   3.99
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   ZnFe2Si
_chemical_formula_sum   'Zn1 Fe2 Si1'
_cell_volume   44.94
_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
  Zn  Zn3  1  0.82  0.82  0.82  1.0
  Fe  Fe0  1  0.41  0.41  0.41  1.0
  Fe  Fe1  1  0.23  0.23  0.23  1.0
  Si  Si2  1  0.0  0.0  0.0  1.0

data_ZnFe2Si
_symmetry_space_group_name_H-M   R3m
_cell_length_a   3.99
_cell_length_b   3.99
_cell_length_c   9.78
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   ZnFe2Si
_chemical_formula_sum   'Zn3 Fe6 Si3'
_cell_volume   134.83
_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
  Zn  Zn0  3  0.0  0.0  0.18  1.0
  Fe  Fe1  3  0.0  0.0  0.59  1.0
  Fe  Fe2  3  0.0  0.0  0.77  1.0
  Si  Si3  3  0.0  0.0  0.0  1.0

Zn Fe Fe Si
Zn Fe Fe Si 0 3 + + + 1 2 o o o 
Fe2ZnSi crystallizes in the trigonal R3m space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 7-coordinate geometry to one Fe(2), three equivalent Zn(1), and three equivalent Si(1) atoms. The Fe(1)-Fe(2) bond length is 1.74 Å. All Fe(1)-Zn(1) bond lengths are 2.43 Å. All Fe(1)-Si(1) bond lengths are 2.43 Å. In the second Fe site, Fe(2) is bonded in a 5-coordinate geometry to one Fe(1), three equivalent Zn(1), and one Si(1) atom. All Fe(2)-Zn(1) bond lengths are 2.43 Å. The Fe(2)-Si(1) bond length is 2.28 Å. Zn(1) is bonded in a distorted single-bond geometry to three equivalent Fe(1), three equivalent Fe(2), and one Si(1) atom. The Zn(1)-Si(1) bond length is 1.74 Å. Si(1) is bonded in a distorted single-bond geometry to one Fe(2), three equivalent Fe(1), and one Zn(1) atom.