The compound described by Sr(LaSe2)2 crystallizes in the tetragonal I-42d space group. Sr(1) is bonded to eight equivalent Se(1) atoms to form distorted SrSe8 hexagonal bipyramids that share corners with eight equivalent La(1)Se8 hexagonal bipyramids, edges with four equivalent Sr(1)Se8 hexagonal bipyramids, and faces with eight equivalent La(1)Se8 hexagonal bipyramids. La(1) is bonded to eight equivalent Se(1) atoms to form distorted LaSe8 hexagonal bipyramids that share corners with four equivalent Sr(1)Se8 hexagonal bipyramids, corners with four equivalent La(1)Se8 hexagonal bipyramids, edges with four equivalent La(1)Se8 hexagonal bipyramids, faces with four equivalent Sr(1)Se8 hexagonal bipyramids, and faces with four equivalent La(1)Se8 hexagonal bipyramids. Se(1) is bonded to two equivalent Sr(1) and four equivalent La(1) atoms to form a mixture of distorted corner, edge, and face-sharing SeSr2La4 octahedra. The corner-sharing octahedral tilt angles range from 16-51°. is represented by the CIF card [CIF]
data_Sr(LaSe2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.938
_cell_length_b   7.938
_cell_length_c   7.938
_cell_angle_alpha   109.299
_cell_angle_beta   109.817
_cell_angle_gamma   109.299
_symmetry_Int_Tables_number   1
_cell_volume   385.104
_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
  Sr  Sr0  1  0.125  0.750  0.875  1.0
  Sr  Sr1  1  0.375  0.250  0.625  1.0
  La  La2  1  0.250  0.629  0.379  1.0
  La  La3  1  0.750  0.871  0.121  1.0
  La  La4  1  0.621  0.371  0.250  1.0
  La  La5  1  0.879  0.129  0.750  1.0
  Se  Se6  1  0.507  0.999  0.356  1.0
  Se  Se7  1  0.143  0.150  0.144  1.0
  Se  Se8  1  0.357  0.501  0.007  1.0
  Se  Se9  1  0.507  0.001  0.857  1.0
  Se  Se10  1  0.644  0.650  0.643  1.0
  Se  Se11  1  0.993  0.850  0.493  1.0
  Se  Se12  1  0.856  0.499  0.007  1.0
  Se  Se13  1  0.993  0.350  0.493  1.0
[/CIF]
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The compound described by Sr(LaSe2)2 crystallizes in the tetragonal I-42d space group. Sr(1) is bonded to eight equivalent Se(1) atoms to form distorted SrSe8 hexagonal bipyramids that share corners with eight equivalent La(1)Se8 hexagonal bipyramids, edges with four equivalent Sr(1)Se8 hexagonal bipyramids, and faces with eight equivalent La(1)Se8 hexagonal bipyramids. La(1) is bonded to eight equivalent Se(1) atoms to form distorted LaSe8 hexagonal bipyramids that share corners with four equivalent Sr(1)Se8 hexagonal bipyramids, corners with four equivalent La(1)Se8 hexagonal bipyramids, edges with four equivalent La(1)Se8 hexagonal bipyramids, faces with four equivalent Sr(1)Se8 hexagonal bipyramids, and faces with four equivalent La(1)Se8 hexagonal bipyramids. Se(1) is bonded to two equivalent Sr(1) and four equivalent La(1) atoms to form a mixture of distorted corner, edge, and face-sharing SeSr2La4 octahedra. The corner-sharing octahedral tilt angles range from 16-51°. is represented by the CIF card [CIF]
data_Sr(LaSe2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.938
_cell_length_b   7.938
_cell_length_c   7.938
_cell_angle_alpha   109.299
_cell_angle_beta   109.817
_cell_angle_gamma   109.299
_symmetry_Int_Tables_number   1
_cell_volume   385.104
_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
  Sr  Sr0  1  0.125  0.750  0.875  1.0
  Sr  Sr1  1  0.375  0.250  0.625  1.0
  La  La2  1  0.250  0.629  0.379  1.0
  La  La3  1  0.750  0.871  0.121  1.0
  La  La4  1  0.621  0.371  0.250  1.0
  La  La5  1  0.879  0.129  0.750  1.0
  Se  Se6  1  0.507  0.999  0.356  1.0
  Se  Se7  1  0.143  0.150  0.144  1.0
  Se  Se8  1  0.357  0.501  0.007  1.0
  Se  Se9  1  0.507  0.001  0.857  1.0
  Se  Se10  1  0.644  0.650  0.643  1.0
  Se  Se11  1  0.993  0.850  0.493  1.0
  Se  Se12  1  0.856  0.499  0.007  1.0
  Se  Se13  1  0.993  0.350  0.493  1.0
[/CIF]
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