The structure described by Ag2Se is Cotunnite structured and crystallizes in the orthorhombic Pnma space group. There are two inequivalent Ag sites. In the first Ag site, Ag(1) is bonded in a 4-coordinate geometry to four equivalent Se(1) atoms. In the second Ag site, Ag(2) is bonded to four equivalent Se(1) atoms to form a mixture of distorted corner and edge-sharing AgSe4 tetrahedra. Se(1) is bonded to four equivalent Ag(1) and four equivalent Ag(2) atoms to form a mixture of distorted corner and edge-sharing SeAg8 hexagonal bipyramids. is represented by the CIF file [CIF]
data_Ag2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.988
_cell_length_b   7.173
_cell_length_c   4.889
_cell_angle_alpha   90.004
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   245.038
_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
  Ag  Ag0  1  0.449  0.920  0.250  1.0
  Ag  Ag1  1  0.051  0.080  0.750  1.0
  Ag  Ag2  1  0.821  0.106  0.250  1.0
  Ag  Ag3  1  0.949  0.580  0.750  1.0
  Ag  Ag4  1  0.321  0.394  0.750  1.0
  Ag  Ag5  1  0.679  0.894  0.750  1.0
  Ag  Ag6  1  0.179  0.606  0.250  1.0
  Ag  Ag7  1  0.551  0.420  0.250  1.0
  Se  Se8  1  0.719  0.283  0.750  1.0
  Se  Se9  1  0.281  0.783  0.750  1.0
  Se  Se10  1  0.219  0.217  0.250  1.0
  Se  Se11  1  0.781  0.717  0.250  1.0
[/CIF]
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The structure described by Ag2Se is Cotunnite structured and crystallizes in the orthorhombic Pnma space group. There are two inequivalent Ag sites. In the first Ag site, Ag(1) is bonded in a 4-coordinate geometry to four equivalent Se(1) atoms. In the second Ag site, Ag(2) is bonded to four equivalent Se(1) atoms to form a mixture of distorted corner and edge-sharing AgSe4 tetrahedra. Se(1) is bonded to four equivalent Ag(1) and four equivalent Ag(2) atoms to form a mixture of distorted corner and edge-sharing SeAg8 hexagonal bipyramids. is represented by the CIF file [CIF]
data_Ag2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.988
_cell_length_b   7.173
_cell_length_c   4.889
_cell_angle_alpha   90.004
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   245.038
_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
  Ag  Ag0  1  0.449  0.920  0.250  1.0
  Ag  Ag1  1  0.051  0.080  0.750  1.0
  Ag  Ag2  1  0.821  0.106  0.250  1.0
  Ag  Ag3  1  0.949  0.580  0.750  1.0
  Ag  Ag4  1  0.321  0.394  0.750  1.0
  Ag  Ag5  1  0.679  0.894  0.750  1.0
  Ag  Ag6  1  0.179  0.606  0.250  1.0
  Ag  Ag7  1  0.551  0.420  0.250  1.0
  Se  Se8  1  0.719  0.283  0.750  1.0
  Se  Se9  1  0.281  0.783  0.750  1.0
  Se  Se10  1  0.219  0.217  0.250  1.0
  Se  Se11  1  0.781  0.717  0.250  1.0
[/CIF]
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