The material described by AgErSe2 crystallizes in the orthorhombic P2_12_12_1 space group. Er(1) is bonded to three equivalent Se(1) and three equivalent Se(2) atoms to form a mixture of edge and corner-sharing ErSe6 octahedra. The corner-sharing octahedral tilt angles range from 43-52°. Ag(1) is bonded in a 4-coordinate geometry to two equivalent Se(1) and two equivalent Se(2) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Er(1) and two equivalent Ag(1) atoms to form a mixture of distorted edge and corner-sharing SeEr3Ag2 trigonal bipyramids. In the second Se site, Se(2) is bonded to three equivalent Er(1) and two equivalent Ag(1) atoms to form a mixture of distorted edge and corner-sharing SeEr3Ag2 trigonal bipyramids. is represented by the CIF card [CIF]
data_ErAgSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.194
_cell_length_b   6.800
_cell_length_c   13.667
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   389.763
_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
  Er  Er0  1  0.225  0.292  0.128  1.0
  Er  Er1  1  0.725  0.208  0.872  1.0
  Er  Er2  1  0.775  0.792  0.372  1.0
  Er  Er3  1  0.275  0.708  0.628  1.0
  Ag  Ag4  1  0.507  0.708  0.874  1.0
  Ag  Ag5  1  0.493  0.208  0.626  1.0
  Ag  Ag6  1  0.007  0.792  0.126  1.0
  Ag  Ag7  1  0.993  0.292  0.374  1.0
  Se  Se8  1  0.769  0.513  0.527  1.0
  Se  Se9  1  0.269  0.987  0.473  1.0
  Se  Se10  1  0.231  0.013  0.973  1.0
  Se  Se11  1  0.731  0.487  0.027  1.0
  Se  Se12  1  0.774  0.913  0.726  1.0
  Se  Se13  1  0.726  0.087  0.226  1.0
  Se  Se14  1  0.226  0.413  0.774  1.0
  Se  Se15  1  0.274  0.587  0.274  1.0
[/CIF]
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The material described by AgErSe2 crystallizes in the orthorhombic P2_12_12_1 space group. Er(1) is bonded to three equivalent Se(1) and three equivalent Se(2) atoms to form a mixture of edge and corner-sharing ErSe6 octahedra. The corner-sharing octahedral tilt angles range from 43-52°. Ag(1) is bonded in a 4-coordinate geometry to two equivalent Se(1) and two equivalent Se(2) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Er(1) and two equivalent Ag(1) atoms to form a mixture of distorted edge and corner-sharing SeEr3Ag2 trigonal bipyramids. In the second Se site, Se(2) is bonded to three equivalent Er(1) and two equivalent Ag(1) atoms to form a mixture of distorted edge and corner-sharing SeEr3Ag2 trigonal bipyramids. is represented by the CIF card [CIF]
data_ErAgSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.194
_cell_length_b   6.800
_cell_length_c   13.667
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   389.763
_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
  Er  Er0  1  0.225  0.292  0.128  1.0
  Er  Er1  1  0.725  0.208  0.872  1.0
  Er  Er2  1  0.775  0.792  0.372  1.0
  Er  Er3  1  0.275  0.708  0.628  1.0
  Ag  Ag4  1  0.507  0.708  0.874  1.0
  Ag  Ag5  1  0.493  0.208  0.626  1.0
  Ag  Ag6  1  0.007  0.792  0.126  1.0
  Ag  Ag7  1  0.993  0.292  0.374  1.0
  Se  Se8  1  0.769  0.513  0.527  1.0
  Se  Se9  1  0.269  0.987  0.473  1.0
  Se  Se10  1  0.231  0.013  0.973  1.0
  Se  Se11  1  0.731  0.487  0.027  1.0
  Se  Se12  1  0.774  0.913  0.726  1.0
  Se  Se13  1  0.726  0.087  0.226  1.0
  Se  Se14  1  0.226  0.413  0.774  1.0
  Se  Se15  1  0.274  0.587  0.274  1.0
[/CIF]
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