The material described by Sr(ErSe2)2 crystallizes in the orthorhombic Pnma space group. Sr(1) is bonded in a 8-coordinate geometry to two equivalent Se(1), two equivalent Se(2), two equivalent Se(3), and two equivalent Se(4) atoms. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded to one Se(3), two equivalent Se(1), and three equivalent Se(4) atoms to form a mixture of corner and edge-sharing ErSe6 octahedra. The corner-sharing octahedral tilt angles range from 48-62°. In the second Er site, Er(2) is bonded to one Se(1), two equivalent Se(3), and three equivalent Se(2) atoms to form a mixture of corner and edge-sharing ErSe6 octahedra. The corner-sharing octahedral tilt angles range from 48-62°. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Sr(1), one Er(2), and two equivalent Er(1) atoms to form a mixture of distorted corner and edge-sharing SeSr2Er3 trigonal bipyramids. In the second Se site, Se(2) is bonded to two equivalent Sr(1) and three equivalent Er(2) atoms to form a mixture of corner and edge-sharing SeSr2Er3 square pyramids. In the third Se site, Se(3) is bonded to two equivalent Sr(1), one Er(1), and two equivalent Er(2) atoms to form a mixture of distorted corner and edge-sharing SeSr2Er3 trigonal bipyramids. In the fourth Se site, Se(4) is bonded to two equivalent Sr(1) and three equivalent Er(1) atoms to form a mixture of distorted corner and edge-sharing SeSr2Er3 trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sr(ErSe2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.105
_cell_length_b   12.535
_cell_length_c   14.835
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   763.303
_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
  Sr  Sr0  1  0.250  0.759  0.335  1.0
  Sr  Sr1  1  0.250  0.259  0.165  1.0
  Sr  Sr2  1  0.750  0.241  0.665  1.0
  Sr  Sr3  1  0.750  0.741  0.835  1.0
  Er  Er4  1  0.250  0.438  0.389  1.0
  Er  Er5  1  0.250  0.938  0.111  1.0
  Er  Er6  1  0.750  0.562  0.611  1.0
  Er  Er7  1  0.750  0.062  0.889  1.0
  Er  Er8  1  0.250  0.417  0.902  1.0
  Er  Er9  1  0.250  0.917  0.598  1.0
  Er  Er10  1  0.750  0.583  0.098  1.0
  Er  Er11  1  0.750  0.083  0.402  1.0
  Se  Se12  1  0.250  0.205  0.830  1.0
  Se  Se13  1  0.250  0.705  0.670  1.0
  Se  Se14  1  0.750  0.795  0.170  1.0
  Se  Se15  1  0.750  0.295  0.330  1.0
  Se  Se16  1  0.250  0.128  0.530  1.0
  Se  Se17  1  0.250  0.628  0.970  1.0
  Se  Se18  1  0.750  0.872  0.470  1.0
  Se  Se19  1  0.750  0.372  0.030  1.0
  Se  Se20  1  0.250  0.027  0.284  1.0
  Se  Se21  1  0.250  0.527  0.216  1.0
  Se  Se22  1  0.750  0.973  0.716  1.0
  Se  Se23  1  0.750  0.473  0.784  1.0
  Se  Se24  1  0.250  0.410  0.577  1.0
  Se  Se25  1  0.250  0.910  0.923  1.0
  Se  Se26  1  0.750  0.590  0.423  1.0
  Se  Se27  1  0.750  0.090  0.077  1.0
[/CIF]
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The material described by Sr(ErSe2)2 crystallizes in the orthorhombic Pnma space group. Sr(1) is bonded in a 8-coordinate geometry to two equivalent Se(1), two equivalent Se(2), two equivalent Se(3), and two equivalent Se(4) atoms. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded to one Se(3), two equivalent Se(1), and three equivalent Se(4) atoms to form a mixture of corner and edge-sharing ErSe6 octahedra. The corner-sharing octahedral tilt angles range from 48-62°. In the second Er site, Er(2) is bonded to one Se(1), two equivalent Se(3), and three equivalent Se(2) atoms to form a mixture of corner and edge-sharing ErSe6 octahedra. The corner-sharing octahedral tilt angles range from 48-62°. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Sr(1), one Er(2), and two equivalent Er(1) atoms to form a mixture of distorted corner and edge-sharing SeSr2Er3 trigonal bipyramids. In the second Se site, Se(2) is bonded to two equivalent Sr(1) and three equivalent Er(2) atoms to form a mixture of corner and edge-sharing SeSr2Er3 square pyramids. In the third Se site, Se(3) is bonded to two equivalent Sr(1), one Er(1), and two equivalent Er(2) atoms to form a mixture of distorted corner and edge-sharing SeSr2Er3 trigonal bipyramids. In the fourth Se site, Se(4) is bonded to two equivalent Sr(1) and three equivalent Er(1) atoms to form a mixture of distorted corner and edge-sharing SeSr2Er3 trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sr(ErSe2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.105
_cell_length_b   12.535
_cell_length_c   14.835
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   763.303
_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
  Sr  Sr0  1  0.250  0.759  0.335  1.0
  Sr  Sr1  1  0.250  0.259  0.165  1.0
  Sr  Sr2  1  0.750  0.241  0.665  1.0
  Sr  Sr3  1  0.750  0.741  0.835  1.0
  Er  Er4  1  0.250  0.438  0.389  1.0
  Er  Er5  1  0.250  0.938  0.111  1.0
  Er  Er6  1  0.750  0.562  0.611  1.0
  Er  Er7  1  0.750  0.062  0.889  1.0
  Er  Er8  1  0.250  0.417  0.902  1.0
  Er  Er9  1  0.250  0.917  0.598  1.0
  Er  Er10  1  0.750  0.583  0.098  1.0
  Er  Er11  1  0.750  0.083  0.402  1.0
  Se  Se12  1  0.250  0.205  0.830  1.0
  Se  Se13  1  0.250  0.705  0.670  1.0
  Se  Se14  1  0.750  0.795  0.170  1.0
  Se  Se15  1  0.750  0.295  0.330  1.0
  Se  Se16  1  0.250  0.128  0.530  1.0
  Se  Se17  1  0.250  0.628  0.970  1.0
  Se  Se18  1  0.750  0.872  0.470  1.0
  Se  Se19  1  0.750  0.372  0.030  1.0
  Se  Se20  1  0.250  0.027  0.284  1.0
  Se  Se21  1  0.250  0.527  0.216  1.0
  Se  Se22  1  0.750  0.973  0.716  1.0
  Se  Se23  1  0.750  0.473  0.784  1.0
  Se  Se24  1  0.250  0.410  0.577  1.0
  Se  Se25  1  0.250  0.910  0.923  1.0
  Se  Se26  1  0.750  0.590  0.423  1.0
  Se  Se27  1  0.750  0.090  0.077  1.0
[/CIF]
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