The material described by AgErSe2 is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. Er(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form ErSe6 octahedra that share corners with six equivalent Er(1)Se6 octahedra, edges with four equivalent Er(1)Se6 octahedra, and edges with eight equivalent Ag(1)Se6 octahedra. The corner-sharing octahedra are not tilted. Ag(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form AgSe6 octahedra that share corners with six equivalent Ag(1)Se6 octahedra, edges with four equivalent Ag(1)Se6 octahedra, and edges with eight equivalent Er(1)Se6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to four equivalent Er(1) and two equivalent Ag(1) atoms to form SeEr4Ag2 octahedra that share corners with six equivalent Se(1)Er4Ag2 octahedra, edges with four equivalent Se(1)Er4Ag2 octahedra, and edges with eight equivalent Se(2)Er2Ag4 octahedra. The corner-sharing octahedra are not tilted. In the second Se site, Se(2) is bonded to two equivalent Er(1) and four equivalent Ag(1) atoms to form SeEr2Ag4 octahedra that share corners with six equivalent Se(2)Er2Ag4 octahedra, edges with four equivalent Se(2)Er2Ag4 octahedra, and edges with eight equivalent Se(1)Er4Ag2 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF card [CIF]
data_ErAgSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.086
_cell_length_b   4.086
_cell_length_c   5.677
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   94.755
_cell_formula_units_Z   1
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  0.500  0.500  0.000  1.0
  Ag  Ag1  1  0.000  0.000  0.500  1.0
  Se  Se2  1  0.000  0.000  0.000  1.0
  Se  Se3  1  0.500  0.500  0.500  1.0
[/CIF]
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The material described by AgErSe2 is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. Er(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form ErSe6 octahedra that share corners with six equivalent Er(1)Se6 octahedra, edges with four equivalent Er(1)Se6 octahedra, and edges with eight equivalent Ag(1)Se6 octahedra. The corner-sharing octahedra are not tilted. Ag(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form AgSe6 octahedra that share corners with six equivalent Ag(1)Se6 octahedra, edges with four equivalent Ag(1)Se6 octahedra, and edges with eight equivalent Er(1)Se6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to four equivalent Er(1) and two equivalent Ag(1) atoms to form SeEr4Ag2 octahedra that share corners with six equivalent Se(1)Er4Ag2 octahedra, edges with four equivalent Se(1)Er4Ag2 octahedra, and edges with eight equivalent Se(2)Er2Ag4 octahedra. The corner-sharing octahedra are not tilted. In the second Se site, Se(2) is bonded to two equivalent Er(1) and four equivalent Ag(1) atoms to form SeEr2Ag4 octahedra that share corners with six equivalent Se(2)Er2Ag4 octahedra, edges with four equivalent Se(2)Er2Ag4 octahedra, and edges with eight equivalent Se(1)Er4Ag2 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF card [CIF]
data_ErAgSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.086
_cell_length_b   4.086
_cell_length_c   5.677
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   94.755
_cell_formula_units_Z   1
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  0.500  0.500  0.000  1.0
  Ag  Ag1  1  0.000  0.000  0.500  1.0
  Se  Se2  1  0.000  0.000  0.000  1.0
  Se  Se3  1  0.500  0.500  0.500  1.0
[/CIF]
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