data_Zr2FeSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.21
_cell_length_b   3.21
_cell_length_c   6.95
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Zr2FeSe
_chemical_formula_sum   'Zr2 Fe1 Se1'
_cell_volume   71.69
_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
  Zr  Zr2  1  0.61  0.61  0.36  1.0
  Zr  Zr3  1  0.61  0.61  0.59  1.0
  Fe  Fe0  1  0.0  0.0  0.0  1.0
  Se  Se1  1  0.0  0.0  0.47  1.0

data_Zr2FeSe
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.54
_cell_length_b   4.54
_cell_length_c   6.95
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Zr2FeSe
_chemical_formula_sum   'Zr4 Fe2 Se2'
_cell_volume   143.38
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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
  Zr  Zr0  2  0.11  0.5  0.36  1.0
  Zr  Zr1  2  0.11  0.5  0.59  1.0
  Fe  Fe2  2  0.0  0.0  0.0  1.0
  Se  Se3  2  0.0  0.0  0.47  1.0

Zr Zr Fe Se
Zr Zr Fe Se 0 3 + + o 0 1 o o o 0 2 + + o 0 2 + o o 0 2 o + o 0 2 o o o 1 3 + + o 1 2 + + + 1 2 + o + 1 2 o + + 2 2 + o o 2 2 o + o 2 3 o o - 2 3 o o o 
Zr2FeSe crystallizes in the monoclinic Cm space group. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 1-coordinate geometry to four equivalent Fe(1) and one Se(1) atom. There are a spread of Zr(1)-Fe(1) bond distances ranging from 3.06-3.70 Å. The Zr(1)-Se(1) bond length is 1.97 Å. In the second Zr site, Zr(2) is bonded in a 1-coordinate geometry to three equivalent Fe(1) and one Se(1) atom. There is one shorter (3.35 Å) and two longer (3.66 Å) Zr(2)-Fe(1) bond lengths. The Zr(2)-Se(1) bond length is 1.97 Å. Fe(1) is bonded in a 12-coordinate geometry to three equivalent Zr(2), four equivalent Zr(1), four equivalent Fe(1), and one Se(1) atom. All Fe(1)-Fe(1) bond lengths are 3.21 Å. The Fe(1)-Se(1) bond length is 3.30 Å. Se(1) is bonded in a 2-coordinate geometry to one Zr(1), one Zr(2), and one Fe(1) atom.