The compound described by Hf2Se3 crystallizes in the monoclinic Cc space group. There are four inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), one Se(5), and one Se(6) atom to form a mixture of edge, face, and corner-sharing HfSe6 octahedra. The corner-sharing octahedral tilt angles range from 7-47°. In the second Hf site, Hf(2) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), one Se(5), and one Se(6) atom to form a mixture of edge, face, and corner-sharing HfSe6 octahedra. The corner-sharing octahedral tilt angles are 7°. In the third Hf site, Hf(3) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), one Se(5), and one Se(6) atom to form a mixture of edge and corner-sharing HfSe6 octahedra. The corner-sharing octahedral tilt angles range from 8-47°. In the fourth Hf site, Hf(4) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), one Se(5), and one Se(6) atom to form a mixture of edge and corner-sharing HfSe6 octahedra. The corner-sharing octahedral tilt angles range from 8-47°. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded in a rectangular see-saw-like geometry to one Hf(1), one Hf(2), one Hf(3), and one Hf(4) atom. In the second Se site, Se(2) is bonded in a rectangular see-saw-like geometry to one Hf(1), one Hf(2), one Hf(3), and one Hf(4) atom. In the third Se site, Se(3) is bonded in a rectangular see-saw-like geometry to one Hf(1), one Hf(2), one Hf(3), and one Hf(4) atom. In the fourth Se site, Se(4) is bonded in a rectangular see-saw-like geometry to one Hf(1), one Hf(2), one Hf(3), and one Hf(4) atom. In the fifth Se site, Se(5) is bonded in a rectangular see-saw-like geometry to one Hf(1), one Hf(2), one Hf(3), and one Hf(4) atom. In the sixth Se site, Se(6) is bonded in a rectangular see-saw-like geometry to one Hf(1), one Hf(2), one Hf(3), and one Hf(4) atom. is represented by the CIF file [CIF]
data_Hf2Se3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.433
_cell_length_b   13.060
_cell_length_c   6.438
_cell_angle_alpha   75.714
_cell_angle_beta   119.981
_cell_angle_gamma   104.249
_symmetry_Int_Tables_number   1
_cell_volume   449.168
_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
  Hf  Hf0  1  0.745  0.232  0.925  1.0
  Hf  Hf1  1  0.913  0.732  0.425  1.0
  Hf  Hf2  1  0.833  0.499  0.836  1.0
  Hf  Hf3  1  0.170  0.498  0.500  1.0
  Hf  Hf4  1  0.497  0.498  0.164  1.0
  Hf  Hf5  1  0.666  0.998  0.665  1.0
  Hf  Hf6  1  0.002  0.999  0.337  1.0
  Hf  Hf7  1  0.328  0.998  0.000  1.0
  Se  Se8  1  0.623  0.871  0.043  1.0
  Se  Se9  1  0.289  0.867  0.376  1.0
  Se  Se10  1  0.954  0.867  0.712  1.0
  Se  Se11  1  0.454  0.367  0.876  1.0
  Se  Se12  1  0.124  0.367  0.212  1.0
  Se  Se13  1  0.791  0.371  0.542  1.0
  Se  Se14  1  0.706  0.128  0.303  1.0
  Se  Se15  1  0.366  0.127  0.614  1.0
  Se  Se16  1  0.053  0.128  0.956  1.0
  Se  Se17  1  0.876  0.627  0.114  1.0
  Se  Se18  1  0.530  0.628  0.455  1.0
  Se  Se19  1  0.223  0.627  0.802  1.0
[/CIF]
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The compound described by Hf2Se3 crystallizes in the monoclinic Cc space group. There are four inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), one Se(5), and one Se(6) atom to form a mixture of edge, face, and corner-sharing HfSe6 octahedra. The corner-sharing octahedral tilt angles range from 7-47°. In the second Hf site, Hf(2) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), one Se(5), and one Se(6) atom to form a mixture of edge, face, and corner-sharing HfSe6 octahedra. The corner-sharing octahedral tilt angles are 7°. In the third Hf site, Hf(3) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), one Se(5), and one Se(6) atom to form a mixture of edge and corner-sharing HfSe6 octahedra. The corner-sharing octahedral tilt angles range from 8-47°. In the fourth Hf site, Hf(4) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), one Se(5), and one Se(6) atom to form a mixture of edge and corner-sharing HfSe6 octahedra. The corner-sharing octahedral tilt angles range from 8-47°. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded in a rectangular see-saw-like geometry to one Hf(1), one Hf(2), one Hf(3), and one Hf(4) atom. In the second Se site, Se(2) is bonded in a rectangular see-saw-like geometry to one Hf(1), one Hf(2), one Hf(3), and one Hf(4) atom. In the third Se site, Se(3) is bonded in a rectangular see-saw-like geometry to one Hf(1), one Hf(2), one Hf(3), and one Hf(4) atom. In the fourth Se site, Se(4) is bonded in a rectangular see-saw-like geometry to one Hf(1), one Hf(2), one Hf(3), and one Hf(4) atom. In the fifth Se site, Se(5) is bonded in a rectangular see-saw-like geometry to one Hf(1), one Hf(2), one Hf(3), and one Hf(4) atom. In the sixth Se site, Se(6) is bonded in a rectangular see-saw-like geometry to one Hf(1), one Hf(2), one Hf(3), and one Hf(4) atom. is represented by the CIF file [CIF]
data_Hf2Se3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.433
_cell_length_b   13.060
_cell_length_c   6.438
_cell_angle_alpha   75.714
_cell_angle_beta   119.981
_cell_angle_gamma   104.249
_symmetry_Int_Tables_number   1
_cell_volume   449.168
_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
  Hf  Hf0  1  0.745  0.232  0.925  1.0
  Hf  Hf1  1  0.913  0.732  0.425  1.0
  Hf  Hf2  1  0.833  0.499  0.836  1.0
  Hf  Hf3  1  0.170  0.498  0.500  1.0
  Hf  Hf4  1  0.497  0.498  0.164  1.0
  Hf  Hf5  1  0.666  0.998  0.665  1.0
  Hf  Hf6  1  0.002  0.999  0.337  1.0
  Hf  Hf7  1  0.328  0.998  0.000  1.0
  Se  Se8  1  0.623  0.871  0.043  1.0
  Se  Se9  1  0.289  0.867  0.376  1.0
  Se  Se10  1  0.954  0.867  0.712  1.0
  Se  Se11  1  0.454  0.367  0.876  1.0
  Se  Se12  1  0.124  0.367  0.212  1.0
  Se  Se13  1  0.791  0.371  0.542  1.0
  Se  Se14  1  0.706  0.128  0.303  1.0
  Se  Se15  1  0.366  0.127  0.614  1.0
  Se  Se16  1  0.053  0.128  0.956  1.0
  Se  Se17  1  0.876  0.627  0.114  1.0
  Se  Se18  1  0.530  0.628  0.455  1.0
  Se  Se19  1  0.223  0.627  0.802  1.0
[/CIF]
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