The material structure described by U2FeSe5 crystallizes in the monoclinic C2/c space group. U(1) is bonded in a 8-coordinate geometry to two equivalent Se(1), three equivalent Se(2), and three equivalent Se(3) atoms. Fe(1) is bonded to two equivalent Se(2) and four equivalent Se(3) atoms to form corner-sharing FeSe6 octahedra. The corner-sharing octahedral tilt angles are 40°. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to four equivalent U(1) atoms to form SeU4 trigonal pyramids that share corners with eight equivalent Se(3)U3Fe2 trigonal bipyramids, edges with two equivalent Se(3)U3Fe2 trigonal bipyramids, and edges with two equivalent Se(1)U4 trigonal pyramids. In the second Se site, Se(2) is bonded in a 4-coordinate geometry to three equivalent U(1) and one Fe(1) atom. In the third Se site, Se(3) is bonded to three equivalent U(1) and two equivalent Fe(1) atoms to form distorted SeU3Fe2 trigonal bipyramids that share corners with two equivalent Se(3)U3Fe2 trigonal bipyramids, corners with four equivalent Se(1)U4 trigonal pyramids, edges with five equivalent Se(3)U3Fe2 trigonal bipyramids, and  an edgeedge with one Se(1)U4 trigonal pyramid. is represented by the CIF card [CIF]
data_U2FeSe5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.528
_cell_length_b   7.345
_cell_length_c   8.306
_cell_angle_alpha   97.136
_cell_angle_beta   113.141
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   362.867
_cell_formula_units_Z   2
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  0.896  0.590  0.216  1.0
  U  U1  1  0.680  0.910  0.784  1.0
  U  U2  1  0.104  0.410  0.784  1.0
  U  U3  1  0.320  0.090  0.216  1.0
  Fe  Fe4  1  0.000  0.000  0.500  1.0
  Fe  Fe5  1  0.500  0.500  0.500  1.0
  Se  Se6  1  0.090  0.750  0.000  1.0
  Se  Se7  1  0.910  0.250  0.000  1.0
  Se  Se8  1  0.701  0.928  0.177  1.0
  Se  Se9  1  0.524  0.572  0.823  1.0
  Se  Se10  1  0.299  0.072  0.823  1.0
  Se  Se11  1  0.476  0.428  0.177  1.0
  Se  Se12  1  0.870  0.690  0.562  1.0
  Se  Se13  1  0.308  0.810  0.438  1.0
  Se  Se14  1  0.130  0.310  0.438  1.0
  Se  Se15  1  0.692  0.190  0.562  1.0
[/CIF]
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The material structure described by U2FeSe5 crystallizes in the monoclinic C2/c space group. U(1) is bonded in a 8-coordinate geometry to two equivalent Se(1), three equivalent Se(2), and three equivalent Se(3) atoms. Fe(1) is bonded to two equivalent Se(2) and four equivalent Se(3) atoms to form corner-sharing FeSe6 octahedra. The corner-sharing octahedral tilt angles are 40°. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to four equivalent U(1) atoms to form SeU4 trigonal pyramids that share corners with eight equivalent Se(3)U3Fe2 trigonal bipyramids, edges with two equivalent Se(3)U3Fe2 trigonal bipyramids, and edges with two equivalent Se(1)U4 trigonal pyramids. In the second Se site, Se(2) is bonded in a 4-coordinate geometry to three equivalent U(1) and one Fe(1) atom. In the third Se site, Se(3) is bonded to three equivalent U(1) and two equivalent Fe(1) atoms to form distorted SeU3Fe2 trigonal bipyramids that share corners with two equivalent Se(3)U3Fe2 trigonal bipyramids, corners with four equivalent Se(1)U4 trigonal pyramids, edges with five equivalent Se(3)U3Fe2 trigonal bipyramids, and  an edgeedge with one Se(1)U4 trigonal pyramid. is represented by the CIF card [CIF]
data_U2FeSe5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.528
_cell_length_b   7.345
_cell_length_c   8.306
_cell_angle_alpha   97.136
_cell_angle_beta   113.141
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   362.867
_cell_formula_units_Z   2
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  0.896  0.590  0.216  1.0
  U  U1  1  0.680  0.910  0.784  1.0
  U  U2  1  0.104  0.410  0.784  1.0
  U  U3  1  0.320  0.090  0.216  1.0
  Fe  Fe4  1  0.000  0.000  0.500  1.0
  Fe  Fe5  1  0.500  0.500  0.500  1.0
  Se  Se6  1  0.090  0.750  0.000  1.0
  Se  Se7  1  0.910  0.250  0.000  1.0
  Se  Se8  1  0.701  0.928  0.177  1.0
  Se  Se9  1  0.524  0.572  0.823  1.0
  Se  Se10  1  0.299  0.072  0.823  1.0
  Se  Se11  1  0.476  0.428  0.177  1.0
  Se  Se12  1  0.870  0.690  0.562  1.0
  Se  Se13  1  0.308  0.810  0.438  1.0
  Se  Se14  1  0.130  0.310  0.438  1.0
  Se  Se15  1  0.692  0.190  0.562  1.0
[/CIF]
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