The material structure described by NaCr5Se8 crystallizes in the monoclinic C2/m space group. Na(1) is bonded in a 4-coordinate geometry to four equivalent Se(2) atoms. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form a mixture of corner and edge-sharing CrSe6 octahedra. The corner-sharing octahedral tilt angles are 49°. In the second Cr site, Cr(2) is bonded to one Se(1), two equivalent Se(2), and three equivalent Se(4) atoms to form a mixture of corner, face, and edge-sharing CrSe6 octahedra. The corner-sharing octahedral tilt angles range from 49-51°. In the third Cr site, Cr(3) is bonded to one Se(1), two equivalent Se(4), and three equivalent Se(3) atoms to form a mixture of corner, face, and edge-sharing CrSe6 octahedra. The corner-sharing octahedral tilt angles range from 49-51°. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a rectangular see-saw-like geometry to one Cr(2), one Cr(3), and two equivalent Cr(1) atoms. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to two equivalent Na(1), one Cr(1), and two equivalent Cr(2) atoms. In the third Se site, Se(3) is bonded in a distorted T-shaped geometry to three equivalent Cr(3) atoms. In the fourth Se site, Se(4) is bonded to two equivalent Cr(3) and three equivalent Cr(2) atoms to form distorted edge-sharing SeCr5 trigonal bipyramids. is represented by the CIF card [CIF]
data_NaCr5Se8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.638
_cell_length_b   9.638
_cell_length_c   9.004
_cell_angle_alpha   75.174
_cell_angle_beta   75.174
_cell_angle_gamma   22.090
_symmetry_Int_Tables_number   1
_cell_volume   303.678
_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
  Na  Na0  1  0.500  0.500  0.500  1.0
  Cr  Cr1  1  0.000  0.000  0.000  1.0
  Cr  Cr2  1  0.342  0.342  0.978  1.0
  Cr  Cr3  1  0.658  0.658  0.022  1.0
  Cr  Cr4  1  0.296  0.296  0.335  1.0
  Cr  Cr5  1  0.704  0.704  0.665  1.0
  Se  Se6  1  0.574  0.574  0.841  1.0
  Se  Se7  1  0.426  0.426  0.159  1.0
  Se  Se8  1  0.085  0.085  0.177  1.0
  Se  Se9  1  0.915  0.915  0.823  1.0
  Se  Se10  1  0.169  0.169  0.509  1.0
  Se  Se11  1  0.831  0.831  0.491  1.0
  Se  Se12  1  0.239  0.239  0.842  1.0
  Se  Se13  1  0.761  0.761  0.158  1.0
[/CIF]
.
The material structure described by NaCr5Se8 crystallizes in the monoclinic C2/m space group. Na(1) is bonded in a 4-coordinate geometry to four equivalent Se(2) atoms. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form a mixture of corner and edge-sharing CrSe6 octahedra. The corner-sharing octahedral tilt angles are 49°. In the second Cr site, Cr(2) is bonded to one Se(1), two equivalent Se(2), and three equivalent Se(4) atoms to form a mixture of corner, face, and edge-sharing CrSe6 octahedra. The corner-sharing octahedral tilt angles range from 49-51°. In the third Cr site, Cr(3) is bonded to one Se(1), two equivalent Se(4), and three equivalent Se(3) atoms to form a mixture of corner, face, and edge-sharing CrSe6 octahedra. The corner-sharing octahedral tilt angles range from 49-51°. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a rectangular see-saw-like geometry to one Cr(2), one Cr(3), and two equivalent Cr(1) atoms. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to two equivalent Na(1), one Cr(1), and two equivalent Cr(2) atoms. In the third Se site, Se(3) is bonded in a distorted T-shaped geometry to three equivalent Cr(3) atoms. In the fourth Se site, Se(4) is bonded to two equivalent Cr(3) and three equivalent Cr(2) atoms to form distorted edge-sharing SeCr5 trigonal bipyramids. is represented by the CIF card [CIF]
data_NaCr5Se8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.638
_cell_length_b   9.638
_cell_length_c   9.004
_cell_angle_alpha   75.174
_cell_angle_beta   75.174
_cell_angle_gamma   22.090
_symmetry_Int_Tables_number   1
_cell_volume   303.678
_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
  Na  Na0  1  0.500  0.500  0.500  1.0
  Cr  Cr1  1  0.000  0.000  0.000  1.0
  Cr  Cr2  1  0.342  0.342  0.978  1.0
  Cr  Cr3  1  0.658  0.658  0.022  1.0
  Cr  Cr4  1  0.296  0.296  0.335  1.0
  Cr  Cr5  1  0.704  0.704  0.665  1.0
  Se  Se6  1  0.574  0.574  0.841  1.0
  Se  Se7  1  0.426  0.426  0.159  1.0
  Se  Se8  1  0.085  0.085  0.177  1.0
  Se  Se9  1  0.915  0.915  0.823  1.0
  Se  Se10  1  0.169  0.169  0.509  1.0
  Se  Se11  1  0.831  0.831  0.491  1.0
  Se  Se12  1  0.239  0.239  0.842  1.0
  Se  Se13  1  0.761  0.761  0.158  1.0
[/CIF]
.