The crystal structure described by Nd5CuSe8 crystallizes in the tetragonal I-4 space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 8-coordinate geometry to four equivalent Se(1) and four equivalent Se(2) atoms. In the second Nd site, Nd(2) is bonded in a 8-coordinate geometry to four equivalent Se(1) and four equivalent Se(2) atoms. Cu(1) is bonded in a square co-planar geometry to four equivalent Se(1) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one Nd(2), four equivalent Nd(1), and one Cu(1) atom to form distorted SeNd5Cu octahedra that share corners with seven equivalent Se(1)Nd5Cu octahedra, corners with eight equivalent Se(2)Nd5 square pyramids, edges with four equivalent Se(1)Nd5Cu octahedra, edges with three equivalent Se(2)Nd5 square pyramids,  a faceface with one Se(1)Nd5Cu octahedra, and faces with two equivalent Se(2)Nd5 square pyramids. The corner-sharing octahedral tilt angles range from 16-48°. In the second Se site, Se(2) is bonded to one Nd(2) and four equivalent Nd(1) atoms to form distorted SeNd5 square pyramids that share corners with eight equivalent Se(1)Nd5Cu octahedra, corners with five equivalent Se(2)Nd5 square pyramids, edges with three equivalent Se(1)Nd5Cu octahedra, edges with five equivalent Se(2)Nd5 square pyramids, and faces with two equivalent Se(1)Nd5Cu octahedra. The corner-sharing octahedral tilt angles range from 20-89°. is represented by the CIF file [CIF]
data_Nd5CuSe8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.701
_cell_length_b   7.701
_cell_length_c   7.701
_cell_angle_alpha   110.315
_cell_angle_beta   110.315
_cell_angle_gamma   107.797
_symmetry_Int_Tables_number   1
_cell_volume   351.285
_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
  Nd  Nd0  1  0.379  0.761  0.877  1.0
  Nd  Nd1  1  0.498  0.621  0.381  1.0
  Nd  Nd2  1  0.883  0.502  0.123  1.0
  Nd  Nd3  1  0.750  0.250  0.500  1.0
  Nd  Nd4  1  0.239  0.117  0.619  1.0
  Cu  Cu5  1  0.000  0.000  0.000  1.0
  Se  Se6  1  0.262  0.891  0.240  1.0
  Se  Se7  1  0.761  0.865  0.259  1.0
  Se  Se8  1  0.135  0.393  0.896  1.0
  Se  Se9  1  0.978  0.738  0.629  1.0
  Se  Se10  1  0.607  0.502  0.741  1.0
  Se  Se11  1  0.498  0.239  0.104  1.0
  Se  Se12  1  0.109  0.349  0.371  1.0
  Se  Se13  1  0.651  0.022  0.760  1.0
[/CIF]
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The crystal structure described by Nd5CuSe8 crystallizes in the tetragonal I-4 space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 8-coordinate geometry to four equivalent Se(1) and four equivalent Se(2) atoms. In the second Nd site, Nd(2) is bonded in a 8-coordinate geometry to four equivalent Se(1) and four equivalent Se(2) atoms. Cu(1) is bonded in a square co-planar geometry to four equivalent Se(1) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one Nd(2), four equivalent Nd(1), and one Cu(1) atom to form distorted SeNd5Cu octahedra that share corners with seven equivalent Se(1)Nd5Cu octahedra, corners with eight equivalent Se(2)Nd5 square pyramids, edges with four equivalent Se(1)Nd5Cu octahedra, edges with three equivalent Se(2)Nd5 square pyramids,  a faceface with one Se(1)Nd5Cu octahedra, and faces with two equivalent Se(2)Nd5 square pyramids. The corner-sharing octahedral tilt angles range from 16-48°. In the second Se site, Se(2) is bonded to one Nd(2) and four equivalent Nd(1) atoms to form distorted SeNd5 square pyramids that share corners with eight equivalent Se(1)Nd5Cu octahedra, corners with five equivalent Se(2)Nd5 square pyramids, edges with three equivalent Se(1)Nd5Cu octahedra, edges with five equivalent Se(2)Nd5 square pyramids, and faces with two equivalent Se(1)Nd5Cu octahedra. The corner-sharing octahedral tilt angles range from 20-89°. is represented by the CIF file [CIF]
data_Nd5CuSe8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.701
_cell_length_b   7.701
_cell_length_c   7.701
_cell_angle_alpha   110.315
_cell_angle_beta   110.315
_cell_angle_gamma   107.797
_symmetry_Int_Tables_number   1
_cell_volume   351.285
_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
  Nd  Nd0  1  0.379  0.761  0.877  1.0
  Nd  Nd1  1  0.498  0.621  0.381  1.0
  Nd  Nd2  1  0.883  0.502  0.123  1.0
  Nd  Nd3  1  0.750  0.250  0.500  1.0
  Nd  Nd4  1  0.239  0.117  0.619  1.0
  Cu  Cu5  1  0.000  0.000  0.000  1.0
  Se  Se6  1  0.262  0.891  0.240  1.0
  Se  Se7  1  0.761  0.865  0.259  1.0
  Se  Se8  1  0.135  0.393  0.896  1.0
  Se  Se9  1  0.978  0.738  0.629  1.0
  Se  Se10  1  0.607  0.502  0.741  1.0
  Se  Se11  1  0.498  0.239  0.104  1.0
  Se  Se12  1  0.109  0.349  0.371  1.0
  Se  Se13  1  0.651  0.022  0.760  1.0
[/CIF]
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