The material described by Na3Sm2(SiSe3)2 crystallizes in the monoclinic C2/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form distorted NaSe6 octahedra that share corners with four equivalent Sm(1)Se6 octahedra, edges with four equivalent Sm(1)Se6 octahedra, and edges with six equivalent Na(2)Se6 octahedra. The corner-sharing octahedral tilt angles are 3°. In the second Na site, Na(2) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form distorted NaSe6 octahedra that share corners with four equivalent Sm(1)Se6 octahedra, edges with three equivalent Na(1)Se6 octahedra, edges with three equivalent Na(2)Se6 octahedra, and edges with four equivalent Sm(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 2-3°. 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 Na(2)Se6 octahedra, edges with two equivalent Na(1)Se6 octahedra, edges with three equivalent Sm(1)Se6 octahedra, and edges with four equivalent Na(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 2-3°. Si(1) is bonded in a 3-coordinate geometry to one Se(1) and two equivalent Se(2) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one Na(1), two equivalent Na(2), two equivalent Sm(1), and one Si(1) atom to form a mixture of corner and edge-sharing SeNa3Sm2Si octahedra. The corner-sharing octahedral tilt angles range from 0-88°. In the second Se site, Se(2) is bonded to one Na(1), two equivalent Na(2), two equivalent Sm(1), and one Si(1) atom to form a mixture of corner and edge-sharing SeNa3Sm2Si octahedra. The corner-sharing octahedral tilt angles range from 0-88°. is represented by the CIF card [CIF]
data_Na3Sm2(SiSe3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.340
_cell_length_b   7.340
_cell_length_c   7.676
_cell_angle_alpha   80.813
_cell_angle_beta   80.813
_cell_angle_gamma   119.923
_symmetry_Int_Tables_number   1
_cell_volume   339.673
_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
  Na  Na1  1  0.671  0.329  0.000  1.0
  Na  Na2  1  0.329  0.671  0.000  1.0
  Sm  Sm3  1  0.834  0.166  0.500  1.0
  Sm  Sm4  1  0.166  0.834  0.500  1.0
  Si  Si5  1  0.556  0.556  0.330  1.0
  Si  Si6  1  0.444  0.444  0.670  1.0
  Se  Se7  1  0.234  0.234  0.262  1.0
  Se  Se8  1  0.766  0.766  0.738  1.0
  Se  Se9  1  0.578  0.922  0.265  1.0
  Se  Se10  1  0.422  0.078  0.735  1.0
  Se  Se11  1  0.078  0.422  0.735  1.0
  Se  Se12  1  0.922  0.578  0.265  1.0
[/CIF]
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The material described by Na3Sm2(SiSe3)2 crystallizes in the monoclinic C2/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form distorted NaSe6 octahedra that share corners with four equivalent Sm(1)Se6 octahedra, edges with four equivalent Sm(1)Se6 octahedra, and edges with six equivalent Na(2)Se6 octahedra. The corner-sharing octahedral tilt angles are 3°. In the second Na site, Na(2) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form distorted NaSe6 octahedra that share corners with four equivalent Sm(1)Se6 octahedra, edges with three equivalent Na(1)Se6 octahedra, edges with three equivalent Na(2)Se6 octahedra, and edges with four equivalent Sm(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 2-3°. 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 Na(2)Se6 octahedra, edges with two equivalent Na(1)Se6 octahedra, edges with three equivalent Sm(1)Se6 octahedra, and edges with four equivalent Na(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 2-3°. Si(1) is bonded in a 3-coordinate geometry to one Se(1) and two equivalent Se(2) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one Na(1), two equivalent Na(2), two equivalent Sm(1), and one Si(1) atom to form a mixture of corner and edge-sharing SeNa3Sm2Si octahedra. The corner-sharing octahedral tilt angles range from 0-88°. In the second Se site, Se(2) is bonded to one Na(1), two equivalent Na(2), two equivalent Sm(1), and one Si(1) atom to form a mixture of corner and edge-sharing SeNa3Sm2Si octahedra. The corner-sharing octahedral tilt angles range from 0-88°. is represented by the CIF card [CIF]
data_Na3Sm2(SiSe3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.340
_cell_length_b   7.340
_cell_length_c   7.676
_cell_angle_alpha   80.813
_cell_angle_beta   80.813
_cell_angle_gamma   119.923
_symmetry_Int_Tables_number   1
_cell_volume   339.673
_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
  Na  Na1  1  0.671  0.329  0.000  1.0
  Na  Na2  1  0.329  0.671  0.000  1.0
  Sm  Sm3  1  0.834  0.166  0.500  1.0
  Sm  Sm4  1  0.166  0.834  0.500  1.0
  Si  Si5  1  0.556  0.556  0.330  1.0
  Si  Si6  1  0.444  0.444  0.670  1.0
  Se  Se7  1  0.234  0.234  0.262  1.0
  Se  Se8  1  0.766  0.766  0.738  1.0
  Se  Se9  1  0.578  0.922  0.265  1.0
  Se  Se10  1  0.422  0.078  0.735  1.0
  Se  Se11  1  0.078  0.422  0.735  1.0
  Se  Se12  1  0.922  0.578  0.265  1.0
[/CIF]
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