The compound described by SmY4Se5 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. Sm(1) is bonded to six equivalent Se(1) atoms to form SmSe6 octahedra that share corners with six equivalent Y(1)Se6 octahedra, edges with six equivalent Sm(1)Se6 octahedra, and edges with six equivalent Y(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to three equivalent Se(1) and three equivalent Se(2) atoms to form YSe6 octahedra that share corners with three equivalent Sm(1)Se6 octahedra, corners with three equivalent Y(2)Se6 octahedra, edges with three equivalent Sm(1)Se6 octahedra, edges with three equivalent Y(2)Se6 octahedra, and edges with six equivalent Y(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Y site, Y(2) is bonded to three equivalent Se(2) and three equivalent Se(3) atoms to form a mixture of corner and edge-sharing YSe6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Sm(1) and three equivalent Y(1) atoms to form SeSm3Y3 octahedra that share corners with three equivalent Se(1)Sm3Y3 octahedra, corners with three equivalent Se(2)Y6 octahedra, edges with three equivalent Se(2)Y6 octahedra, and edges with nine equivalent Se(1)Sm3Y3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second Se site, Se(2) is bonded to three equivalent Y(1) and three equivalent Y(2) atoms to form SeY6 octahedra that share corners with three equivalent Se(1)Sm3Y3 octahedra, corners with three equivalent Se(3)Y6 octahedra, edges with three equivalent Se(1)Sm3Y3 octahedra, edges with three equivalent Se(3)Y6 octahedra, and edges with six equivalent Se(2)Y6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the third Se site, Se(3) is bonded to six equivalent Y(2) atoms to form a mixture of corner and edge-sharing SeY6 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF card [CIF]
data_SmY4Se5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   16.970
_cell_length_b   16.970
_cell_length_c   16.970
_cell_angle_alpha   13.804
_cell_angle_beta   13.804
_cell_angle_gamma   13.804
_symmetry_Int_Tables_number   1
_cell_volume   242.108
_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
  Sm  Sm0  1  0.000  0.000  0.000  1.0
  Y  Y1  1  0.599  0.599  0.599  1.0
  Y  Y2  1  0.200  0.200  0.200  1.0
  Y  Y3  1  0.800  0.800  0.800  1.0
  Y  Y4  1  0.401  0.401  0.401  1.0
  Se  Se5  1  0.702  0.702  0.702  1.0
  Se  Se6  1  0.101  0.101  0.101  1.0
  Se  Se7  1  0.500  0.500  0.500  1.0
  Se  Se8  1  0.298  0.298  0.298  1.0
  Se  Se9  1  0.899  0.899  0.899  1.0
[/CIF]
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The compound described by SmY4Se5 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. Sm(1) is bonded to six equivalent Se(1) atoms to form SmSe6 octahedra that share corners with six equivalent Y(1)Se6 octahedra, edges with six equivalent Sm(1)Se6 octahedra, and edges with six equivalent Y(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to three equivalent Se(1) and three equivalent Se(2) atoms to form YSe6 octahedra that share corners with three equivalent Sm(1)Se6 octahedra, corners with three equivalent Y(2)Se6 octahedra, edges with three equivalent Sm(1)Se6 octahedra, edges with three equivalent Y(2)Se6 octahedra, and edges with six equivalent Y(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Y site, Y(2) is bonded to three equivalent Se(2) and three equivalent Se(3) atoms to form a mixture of corner and edge-sharing YSe6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Sm(1) and three equivalent Y(1) atoms to form SeSm3Y3 octahedra that share corners with three equivalent Se(1)Sm3Y3 octahedra, corners with three equivalent Se(2)Y6 octahedra, edges with three equivalent Se(2)Y6 octahedra, and edges with nine equivalent Se(1)Sm3Y3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second Se site, Se(2) is bonded to three equivalent Y(1) and three equivalent Y(2) atoms to form SeY6 octahedra that share corners with three equivalent Se(1)Sm3Y3 octahedra, corners with three equivalent Se(3)Y6 octahedra, edges with three equivalent Se(1)Sm3Y3 octahedra, edges with three equivalent Se(3)Y6 octahedra, and edges with six equivalent Se(2)Y6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the third Se site, Se(3) is bonded to six equivalent Y(2) atoms to form a mixture of corner and edge-sharing SeY6 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF card [CIF]
data_SmY4Se5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   16.970
_cell_length_b   16.970
_cell_length_c   16.970
_cell_angle_alpha   13.804
_cell_angle_beta   13.804
_cell_angle_gamma   13.804
_symmetry_Int_Tables_number   1
_cell_volume   242.108
_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
  Sm  Sm0  1  0.000  0.000  0.000  1.0
  Y  Y1  1  0.599  0.599  0.599  1.0
  Y  Y2  1  0.200  0.200  0.200  1.0
  Y  Y3  1  0.800  0.800  0.800  1.0
  Y  Y4  1  0.401  0.401  0.401  1.0
  Se  Se5  1  0.702  0.702  0.702  1.0
  Se  Se6  1  0.101  0.101  0.101  1.0
  Se  Se7  1  0.500  0.500  0.500  1.0
  Se  Se8  1  0.298  0.298  0.298  1.0
  Se  Se9  1  0.899  0.899  0.899  1.0
[/CIF]
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