The structure described by NaSm2Se3 is Caswellsilverite-like structured and crystallizes in the orthorhombic Immm space group. Na(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form NaSe6 octahedra that share corners with two equivalent Na(1)Se6 octahedra, corners with four equivalent Sm(1)Se6 octahedra, edges with two equivalent Na(1)Se6 octahedra, and edges with ten equivalent Sm(1)Se6 octahedra. The corner-sharing octahedra are not tilted. Sm(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form SmSe6 octahedra that share corners with two equivalent Na(1)Se6 octahedra, corners with four equivalent Sm(1)Se6 octahedra, edges with five equivalent Na(1)Se6 octahedra, and edges with seven equivalent Sm(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Na(1) and four equivalent Sm(1) atoms to form a mixture of corner and edge-sharing SeNa2Sm4 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second Se site, Se(2) is bonded to two equivalent Na(1) and four equivalent Sm(1) atoms to form a mixture of corner and edge-sharing SeNa2Sm4 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. is represented by the CIF file [CIF]
data_NaSm2Se3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.258
_cell_length_b   7.258
_cell_length_c   7.258
_cell_angle_alpha   146.751
_cell_angle_beta   132.205
_cell_angle_gamma   59.464
_symmetry_Int_Tables_number   1
_cell_volume   153.927
_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
  Na  Na0  1  0.000  0.000  0.000  1.0
  Sm  Sm1  1  0.664  0.664  0.000  1.0
  Sm  Sm2  1  0.336  0.336  0.000  1.0
  Se  Se3  1  0.500  0.000  0.500  1.0
  Se  Se4  1  0.169  0.669  0.500  1.0
  Se  Se5  1  0.831  0.331  0.500  1.0
[/CIF]
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The structure described by NaSm2Se3 is Caswellsilverite-like structured and crystallizes in the orthorhombic Immm space group. Na(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form NaSe6 octahedra that share corners with two equivalent Na(1)Se6 octahedra, corners with four equivalent Sm(1)Se6 octahedra, edges with two equivalent Na(1)Se6 octahedra, and edges with ten equivalent Sm(1)Se6 octahedra. The corner-sharing octahedra are not tilted. Sm(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form SmSe6 octahedra that share corners with two equivalent Na(1)Se6 octahedra, corners with four equivalent Sm(1)Se6 octahedra, edges with five equivalent Na(1)Se6 octahedra, and edges with seven equivalent Sm(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Na(1) and four equivalent Sm(1) atoms to form a mixture of corner and edge-sharing SeNa2Sm4 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second Se site, Se(2) is bonded to two equivalent Na(1) and four equivalent Sm(1) atoms to form a mixture of corner and edge-sharing SeNa2Sm4 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. is represented by the CIF file [CIF]
data_NaSm2Se3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.258
_cell_length_b   7.258
_cell_length_c   7.258
_cell_angle_alpha   146.751
_cell_angle_beta   132.205
_cell_angle_gamma   59.464
_symmetry_Int_Tables_number   1
_cell_volume   153.927
_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
  Na  Na0  1  0.000  0.000  0.000  1.0
  Sm  Sm1  1  0.664  0.664  0.000  1.0
  Sm  Sm2  1  0.336  0.336  0.000  1.0
  Se  Se3  1  0.500  0.000  0.500  1.0
  Se  Se4  1  0.169  0.669  0.500  1.0
  Se  Se5  1  0.831  0.331  0.500  1.0
[/CIF]
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