The compound described by Cr(FeSe2)2 crystallizes in the monoclinic Cm space group. Cr(1) is bonded to one Se(1), one Se(4), two equivalent Se(2), and two equivalent Se(3) atoms to form distorted CrSe6 octahedra that share corners with six equivalent Fe(1)Se6 octahedra, edges with two equivalent Cr(1)Se6 octahedra, edges with four equivalent Fe(2)Se6 octahedra, and  a faceface with one Fe(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 52-53°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one Se(3), one Se(4), two equivalent Se(1), and two equivalent Se(2) atoms to form FeSe6 octahedra that share corners with six equivalent Cr(1)Se6 octahedra, corners with six equivalent Fe(2)Se6 octahedra, edges with two equivalent Fe(1)Se6 octahedra,  a faceface with one Cr(1)Se6 octahedra, and  a faceface with one Fe(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 50-53°. In the second Fe site, Fe(2) is bonded to one Se(2), one Se(3), two equivalent Se(1), and two equivalent Se(4) atoms to form FeSe6 octahedra that share corners with six equivalent Fe(1)Se6 octahedra, edges with two equivalent Fe(2)Se6 octahedra, edges with four equivalent Cr(1)Se6 octahedra, and  a faceface with one Fe(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 50-52°. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to one Cr(1), two equivalent Fe(1), and two equivalent Fe(2) atoms. In the second Se site, Se(2) is bonded to two equivalent Cr(1), one Fe(2), and two equivalent Fe(1) atoms to form distorted edge-sharing SeCr2Fe3 trigonal bipyramids. In the third Se site, Se(3) is bonded in a rectangular see-saw-like geometry to two equivalent Cr(1), one Fe(1), and one Fe(2) atom. In the fourth Se site, Se(4) is bonded in a rectangular see-saw-like geometry to one Cr(1), one Fe(1), and two equivalent Fe(2) atoms. is represented by the CIF file [CIF]
data_Cr(FeSe2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.544
_cell_length_b   6.263
_cell_length_c   6.604
_cell_angle_alpha   117.510
_cell_angle_beta   74.437
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   123.924
_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
  Cr  Cr0  1  0.758  0.212  0.484  1.0
  Fe  Fe1  1  0.498  0.496  0.004  1.0
  Fe  Fe2  1  0.243  0.790  0.514  1.0
  Se  Se3  1  0.866  0.474  0.268  1.0
  Se  Se4  1  0.133  0.532  0.734  1.0
  Se  Se5  1  0.388  0.944  0.224  1.0
  Se  Se6  1  0.614  0.053  0.772  1.0
[/CIF]
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The compound described by Cr(FeSe2)2 crystallizes in the monoclinic Cm space group. Cr(1) is bonded to one Se(1), one Se(4), two equivalent Se(2), and two equivalent Se(3) atoms to form distorted CrSe6 octahedra that share corners with six equivalent Fe(1)Se6 octahedra, edges with two equivalent Cr(1)Se6 octahedra, edges with four equivalent Fe(2)Se6 octahedra, and  a faceface with one Fe(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 52-53°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one Se(3), one Se(4), two equivalent Se(1), and two equivalent Se(2) atoms to form FeSe6 octahedra that share corners with six equivalent Cr(1)Se6 octahedra, corners with six equivalent Fe(2)Se6 octahedra, edges with two equivalent Fe(1)Se6 octahedra,  a faceface with one Cr(1)Se6 octahedra, and  a faceface with one Fe(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 50-53°. In the second Fe site, Fe(2) is bonded to one Se(2), one Se(3), two equivalent Se(1), and two equivalent Se(4) atoms to form FeSe6 octahedra that share corners with six equivalent Fe(1)Se6 octahedra, edges with two equivalent Fe(2)Se6 octahedra, edges with four equivalent Cr(1)Se6 octahedra, and  a faceface with one Fe(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 50-52°. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to one Cr(1), two equivalent Fe(1), and two equivalent Fe(2) atoms. In the second Se site, Se(2) is bonded to two equivalent Cr(1), one Fe(2), and two equivalent Fe(1) atoms to form distorted edge-sharing SeCr2Fe3 trigonal bipyramids. In the third Se site, Se(3) is bonded in a rectangular see-saw-like geometry to two equivalent Cr(1), one Fe(1), and one Fe(2) atom. In the fourth Se site, Se(4) is bonded in a rectangular see-saw-like geometry to one Cr(1), one Fe(1), and two equivalent Fe(2) atoms. is represented by the CIF file [CIF]
data_Cr(FeSe2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.544
_cell_length_b   6.263
_cell_length_c   6.604
_cell_angle_alpha   117.510
_cell_angle_beta   74.437
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   123.924
_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
  Cr  Cr0  1  0.758  0.212  0.484  1.0
  Fe  Fe1  1  0.498  0.496  0.004  1.0
  Fe  Fe2  1  0.243  0.790  0.514  1.0
  Se  Se3  1  0.866  0.474  0.268  1.0
  Se  Se4  1  0.133  0.532  0.734  1.0
  Se  Se5  1  0.388  0.944  0.224  1.0
  Se  Se6  1  0.614  0.053  0.772  1.0
[/CIF]
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