The crystal structure described by EuSm2Se4 crystallizes in the tetragonal I-42d space group. Eu(1) is bonded to eight equivalent Se(1) atoms to form distorted EuSe8 hexagonal bipyramids that share corners with eight equivalent Sm(1)Se8 hexagonal bipyramids, edges with four equivalent Eu(1)Se8 hexagonal bipyramids, and faces with eight equivalent Sm(1)Se8 hexagonal bipyramids. Sm(1) is bonded to eight equivalent Se(1) atoms to form distorted SmSe8 hexagonal bipyramids that share corners with four equivalent Eu(1)Se8 hexagonal bipyramids, corners with four equivalent Sm(1)Se8 hexagonal bipyramids, edges with four equivalent Sm(1)Se8 hexagonal bipyramids, faces with four equivalent Eu(1)Se8 hexagonal bipyramids, and faces with four equivalent Sm(1)Se8 hexagonal bipyramids. Se(1) is bonded to two equivalent Eu(1) and four equivalent Sm(1) atoms to form a mixture of distorted edge, face, and corner-sharing SeSm4Eu2 octahedra. The corner-sharing octahedral tilt angles range from 17-50°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm2EuSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.728
_cell_length_b   7.728
_cell_length_c   7.728
_cell_angle_alpha   109.359
_cell_angle_beta   109.359
_cell_angle_gamma   109.696
_symmetry_Int_Tables_number   1
_cell_volume   355.336
_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
  Sm  Sm0  1  0.999  0.375  0.124  1.0
  Sm  Sm1  1  0.625  0.749  0.624  1.0
  Sm  Sm2  1  0.251  0.875  0.876  1.0
  Sm  Sm3  1  0.125  0.001  0.376  1.0
  Eu  Eu4  1  0.750  0.250  0.500  1.0
  Eu  Eu5  1  0.500  0.500  0.000  1.0
  Se  Se6  1  0.516  0.117  0.749  1.0
  Se  Se7  1  0.734  0.983  0.101  1.0
  Se  Se8  1  0.883  0.632  0.399  1.0
  Se  Se9  1  0.367  0.266  0.249  1.0
  Se  Se10  1  0.882  0.633  0.899  1.0
  Se  Se11  1  0.233  0.484  0.601  1.0
  Se  Se12  1  0.368  0.767  0.251  1.0
  Se  Se13  1  0.017  0.118  0.751  1.0
[/CIF]
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The crystal structure described by EuSm2Se4 crystallizes in the tetragonal I-42d space group. Eu(1) is bonded to eight equivalent Se(1) atoms to form distorted EuSe8 hexagonal bipyramids that share corners with eight equivalent Sm(1)Se8 hexagonal bipyramids, edges with four equivalent Eu(1)Se8 hexagonal bipyramids, and faces with eight equivalent Sm(1)Se8 hexagonal bipyramids. Sm(1) is bonded to eight equivalent Se(1) atoms to form distorted SmSe8 hexagonal bipyramids that share corners with four equivalent Eu(1)Se8 hexagonal bipyramids, corners with four equivalent Sm(1)Se8 hexagonal bipyramids, edges with four equivalent Sm(1)Se8 hexagonal bipyramids, faces with four equivalent Eu(1)Se8 hexagonal bipyramids, and faces with four equivalent Sm(1)Se8 hexagonal bipyramids. Se(1) is bonded to two equivalent Eu(1) and four equivalent Sm(1) atoms to form a mixture of distorted edge, face, and corner-sharing SeSm4Eu2 octahedra. The corner-sharing octahedral tilt angles range from 17-50°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm2EuSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.728
_cell_length_b   7.728
_cell_length_c   7.728
_cell_angle_alpha   109.359
_cell_angle_beta   109.359
_cell_angle_gamma   109.696
_symmetry_Int_Tables_number   1
_cell_volume   355.336
_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
  Sm  Sm0  1  0.999  0.375  0.124  1.0
  Sm  Sm1  1  0.625  0.749  0.624  1.0
  Sm  Sm2  1  0.251  0.875  0.876  1.0
  Sm  Sm3  1  0.125  0.001  0.376  1.0
  Eu  Eu4  1  0.750  0.250  0.500  1.0
  Eu  Eu5  1  0.500  0.500  0.000  1.0
  Se  Se6  1  0.516  0.117  0.749  1.0
  Se  Se7  1  0.734  0.983  0.101  1.0
  Se  Se8  1  0.883  0.632  0.399  1.0
  Se  Se9  1  0.367  0.266  0.249  1.0
  Se  Se10  1  0.882  0.633  0.899  1.0
  Se  Se11  1  0.233  0.484  0.601  1.0
  Se  Se12  1  0.368  0.767  0.251  1.0
  Se  Se13  1  0.017  0.118  0.751  1.0
[/CIF]
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