The material described by Sr(NdSe2)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 Nd(1)Se8 hexagonal bipyramids, edges with four equivalent Sr(1)Se8 hexagonal bipyramids, and faces with eight equivalent Nd(1)Se8 hexagonal bipyramids. Nd(1) is bonded to eight equivalent Se(1) atoms to form distorted NdSe8 hexagonal bipyramids that share corners with four equivalent Sr(1)Se8 hexagonal bipyramids, corners with four equivalent Nd(1)Se8 hexagonal bipyramids, edges with four equivalent Nd(1)Se8 hexagonal bipyramids, faces with four equivalent Sr(1)Se8 hexagonal bipyramids, and faces with four equivalent Nd(1)Se8 hexagonal bipyramids. Se(1) is bonded to two equivalent Sr(1) and four equivalent Nd(1) atoms to form a mixture of distorted face, corner, and edge-sharing SeSr2Nd4 octahedra. The corner-sharing octahedral tilt angles range from 16-51°. is represented by the CIF file [CIF]
data_Sr(NdSe2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.836
_cell_length_b   7.836
_cell_length_c   7.836
_cell_angle_alpha   109.436
_cell_angle_beta   109.542
_cell_angle_gamma   109.436
_symmetry_Int_Tables_number   1
_cell_volume   370.322
_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
  Nd  Nd2  1  0.250  0.627  0.377  1.0
  Nd  Nd3  1  0.750  0.873  0.123  1.0
  Nd  Nd4  1  0.623  0.373  0.250  1.0
  Nd  Nd5  1  0.877  0.127  0.750  1.0
  Se  Se6  1  0.142  0.151  0.143  1.0
  Se  Se7  1  0.358  0.501  0.009  1.0
  Se  Se8  1  0.643  0.651  0.642  1.0
  Se  Se9  1  0.509  0.001  0.858  1.0
  Se  Se10  1  0.509  0.999  0.357  1.0
  Se  Se11  1  0.991  0.849  0.491  1.0
  Se  Se12  1  0.857  0.499  0.009  1.0
  Se  Se13  1  0.991  0.349  0.491  1.0
[/CIF]
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The material described by Sr(NdSe2)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 Nd(1)Se8 hexagonal bipyramids, edges with four equivalent Sr(1)Se8 hexagonal bipyramids, and faces with eight equivalent Nd(1)Se8 hexagonal bipyramids. Nd(1) is bonded to eight equivalent Se(1) atoms to form distorted NdSe8 hexagonal bipyramids that share corners with four equivalent Sr(1)Se8 hexagonal bipyramids, corners with four equivalent Nd(1)Se8 hexagonal bipyramids, edges with four equivalent Nd(1)Se8 hexagonal bipyramids, faces with four equivalent Sr(1)Se8 hexagonal bipyramids, and faces with four equivalent Nd(1)Se8 hexagonal bipyramids. Se(1) is bonded to two equivalent Sr(1) and four equivalent Nd(1) atoms to form a mixture of distorted face, corner, and edge-sharing SeSr2Nd4 octahedra. The corner-sharing octahedral tilt angles range from 16-51°. is represented by the CIF file [CIF]
data_Sr(NdSe2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.836
_cell_length_b   7.836
_cell_length_c   7.836
_cell_angle_alpha   109.436
_cell_angle_beta   109.542
_cell_angle_gamma   109.436
_symmetry_Int_Tables_number   1
_cell_volume   370.322
_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
  Nd  Nd2  1  0.250  0.627  0.377  1.0
  Nd  Nd3  1  0.750  0.873  0.123  1.0
  Nd  Nd4  1  0.623  0.373  0.250  1.0
  Nd  Nd5  1  0.877  0.127  0.750  1.0
  Se  Se6  1  0.142  0.151  0.143  1.0
  Se  Se7  1  0.358  0.501  0.009  1.0
  Se  Se8  1  0.643  0.651  0.642  1.0
  Se  Se9  1  0.509  0.001  0.858  1.0
  Se  Se10  1  0.509  0.999  0.357  1.0
  Se  Se11  1  0.991  0.849  0.491  1.0
  Se  Se12  1  0.857  0.499  0.009  1.0
  Se  Se13  1  0.991  0.349  0.491  1.0
[/CIF]
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