The crystal structure described by Pr2CrSe4 crystallizes in the monoclinic C2/m space group. Pr(1) is bonded to three equivalent Se(1) and three equivalent Se(2) atoms to form distorted PrSe6 octahedra that share corners with six equivalent Cr(1)Se6 octahedra, edges with six equivalent Pr(1)Se6 octahedra, and  a faceface with one Cr(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 41-58°. Cr(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form CrSe6 octahedra that share corners with twelve equivalent Pr(1)Se6 octahedra, edges with two equivalent Cr(1)Se6 octahedra, and faces with two equivalent Pr(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 41-58°. There are two inequivalent Se sites. In the first Se site, Se(2) is bonded in a rectangular see-saw-like geometry to three equivalent Pr(1) and one Cr(1) atom. In the second Se site, Se(1) is bonded to three equivalent Pr(1) and two equivalent Cr(1) atoms to form a mixture of distorted edge and corner-sharing SePr3Cr2 square pyramids. is represented by the CIF file [CIF]
data_Pr2CrSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.177
_cell_length_b   7.461
_cell_length_c   7.522
_cell_angle_alpha   119.200
_cell_angle_beta   106.121
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   193.987
_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
  Pr  Pr0  1  0.719  0.712  0.437  1.0
  Pr  Pr1  1  0.281  0.288  0.563  1.0
  Cr  Cr2  1  0.000  0.000  0.000  1.0
  Se  Se3  1  0.626  0.995  0.252  1.0
  Se  Se4  1  0.374  0.005  0.748  1.0
  Se  Se5  1  0.892  0.600  0.785  1.0
  Se  Se6  1  0.108  0.400  0.215  1.0
[/CIF]
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The crystal structure described by Pr2CrSe4 crystallizes in the monoclinic C2/m space group. Pr(1) is bonded to three equivalent Se(1) and three equivalent Se(2) atoms to form distorted PrSe6 octahedra that share corners with six equivalent Cr(1)Se6 octahedra, edges with six equivalent Pr(1)Se6 octahedra, and  a faceface with one Cr(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 41-58°. Cr(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form CrSe6 octahedra that share corners with twelve equivalent Pr(1)Se6 octahedra, edges with two equivalent Cr(1)Se6 octahedra, and faces with two equivalent Pr(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 41-58°. There are two inequivalent Se sites. In the first Se site, Se(2) is bonded in a rectangular see-saw-like geometry to three equivalent Pr(1) and one Cr(1) atom. In the second Se site, Se(1) is bonded to three equivalent Pr(1) and two equivalent Cr(1) atoms to form a mixture of distorted edge and corner-sharing SePr3Cr2 square pyramids. is represented by the CIF file [CIF]
data_Pr2CrSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.177
_cell_length_b   7.461
_cell_length_c   7.522
_cell_angle_alpha   119.200
_cell_angle_beta   106.121
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   193.987
_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
  Pr  Pr0  1  0.719  0.712  0.437  1.0
  Pr  Pr1  1  0.281  0.288  0.563  1.0
  Cr  Cr2  1  0.000  0.000  0.000  1.0
  Se  Se3  1  0.626  0.995  0.252  1.0
  Se  Se4  1  0.374  0.005  0.748  1.0
  Se  Se5  1  0.892  0.600  0.785  1.0
  Se  Se6  1  0.108  0.400  0.215  1.0
[/CIF]
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