The material structure described by UNiSe3 crystallizes in the orthorhombic Pnma space group. U(1) is bonded in a 8-coordinate geometry to two equivalent Se(1) and six equivalent Se(2) atoms. Ni(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form corner-sharing NiSe6 octahedra. The corner-sharing octahedral tilt angles range from 41-48°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent U(1) and two equivalent Ni(1) atoms to form distorted corner-sharing SeU2Ni2 trigonal pyramids. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to three equivalent U(1) and two equivalent Ni(1) atoms. is represented by the CIF card [CIF]
data_UNiSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.255
_cell_length_b   7.387
_cell_length_c   8.840
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   408.489
_cell_formula_units_Z   4
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
  U  U0  1  0.434  0.869  0.250  1.0
  U  U1  1  0.066  0.369  0.250  1.0
  U  U2  1  0.566  0.131  0.750  1.0
  U  U3  1  0.934  0.631  0.750  1.0
  Ni  Ni4  1  0.500  0.500  0.000  1.0
  Ni  Ni5  1  0.000  0.000  0.500  1.0
  Ni  Ni6  1  0.500  0.500  0.500  1.0
  Ni  Ni7  1  0.000  0.000  0.000  1.0
  Se  Se8  1  0.649  0.538  0.250  1.0
  Se  Se9  1  0.851  0.038  0.250  1.0
  Se  Se10  1  0.351  0.462  0.750  1.0
  Se  Se11  1  0.149  0.962  0.750  1.0
  Se  Se12  1  0.666  0.828  0.551  1.0
  Se  Se13  1  0.834  0.328  0.949  1.0
  Se  Se14  1  0.334  0.172  0.051  1.0
  Se  Se15  1  0.166  0.672  0.449  1.0
  Se  Se16  1  0.334  0.172  0.449  1.0
  Se  Se17  1  0.166  0.672  0.051  1.0
  Se  Se18  1  0.666  0.828  0.949  1.0
  Se  Se19  1  0.834  0.328  0.551  1.0
[/CIF]
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The material structure described by UNiSe3 crystallizes in the orthorhombic Pnma space group. U(1) is bonded in a 8-coordinate geometry to two equivalent Se(1) and six equivalent Se(2) atoms. Ni(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form corner-sharing NiSe6 octahedra. The corner-sharing octahedral tilt angles range from 41-48°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent U(1) and two equivalent Ni(1) atoms to form distorted corner-sharing SeU2Ni2 trigonal pyramids. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to three equivalent U(1) and two equivalent Ni(1) atoms. is represented by the CIF card [CIF]
data_UNiSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.255
_cell_length_b   7.387
_cell_length_c   8.840
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   408.489
_cell_formula_units_Z   4
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
  U  U0  1  0.434  0.869  0.250  1.0
  U  U1  1  0.066  0.369  0.250  1.0
  U  U2  1  0.566  0.131  0.750  1.0
  U  U3  1  0.934  0.631  0.750  1.0
  Ni  Ni4  1  0.500  0.500  0.000  1.0
  Ni  Ni5  1  0.000  0.000  0.500  1.0
  Ni  Ni6  1  0.500  0.500  0.500  1.0
  Ni  Ni7  1  0.000  0.000  0.000  1.0
  Se  Se8  1  0.649  0.538  0.250  1.0
  Se  Se9  1  0.851  0.038  0.250  1.0
  Se  Se10  1  0.351  0.462  0.750  1.0
  Se  Se11  1  0.149  0.962  0.750  1.0
  Se  Se12  1  0.666  0.828  0.551  1.0
  Se  Se13  1  0.834  0.328  0.949  1.0
  Se  Se14  1  0.334  0.172  0.051  1.0
  Se  Se15  1  0.166  0.672  0.449  1.0
  Se  Se16  1  0.334  0.172  0.449  1.0
  Se  Se17  1  0.166  0.672  0.051  1.0
  Se  Se18  1  0.666  0.828  0.949  1.0
  Se  Se19  1  0.834  0.328  0.551  1.0
[/CIF]
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