The crystal structure described by YSe2 crystallizes in the orthorhombic Immm space group. Y(1) is bonded in a 8-coordinate geometry to four equivalent Se(1) and four equivalent Se(2) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to four equivalent Y(1) atoms to form a mixture of corner and edge-sharing SeY4 trigonal pyramids. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to four equivalent Y(1) and one Se(2) atom. is represented by the CIF card [CIF]
data_YSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.540
_cell_length_b   7.540
_cell_length_c   7.540
_cell_angle_alpha   148.611
_cell_angle_beta   135.807
_cell_angle_gamma   55.205
_symmetry_Int_Tables_number   1
_cell_volume   154.631
_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
  Y  Y0  1  0.849  0.849  0.000  1.0
  Y  Y1  1  0.151  0.151  0.000  1.0
  Se  Se2  1  0.707  0.207  0.500  1.0
  Se  Se3  1  0.293  0.793  0.500  1.0
  Se  Se4  1  0.789  0.500  0.289  1.0
  Se  Se5  1  0.211  0.500  0.711  1.0
[/CIF]
.
The crystal structure described by YSe2 crystallizes in the orthorhombic Immm space group. Y(1) is bonded in a 8-coordinate geometry to four equivalent Se(1) and four equivalent Se(2) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to four equivalent Y(1) atoms to form a mixture of corner and edge-sharing SeY4 trigonal pyramids. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to four equivalent Y(1) and one Se(2) atom. is represented by the CIF card [CIF]
data_YSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.540
_cell_length_b   7.540
_cell_length_c   7.540
_cell_angle_alpha   148.611
_cell_angle_beta   135.807
_cell_angle_gamma   55.205
_symmetry_Int_Tables_number   1
_cell_volume   154.631
_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
  Y  Y0  1  0.849  0.849  0.000  1.0
  Y  Y1  1  0.151  0.151  0.000  1.0
  Se  Se2  1  0.707  0.207  0.500  1.0
  Se  Se3  1  0.293  0.793  0.500  1.0
  Se  Se4  1  0.789  0.500  0.289  1.0
  Se  Se5  1  0.211  0.500  0.711  1.0
[/CIF]
.