The material described by Na9Sm(SiSe3)4 crystallizes in the monoclinic C2 space group. There are six inequivalent Na sites. In the first Na site, Na(1) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), one Se(5), and one Se(6) atom to form NaSe6 octahedra that share  a cornercorner with one Na(4)Se6 octahedra,  a cornercorner with one Na(5)Se6 octahedra,  a cornercorner with one Na(6)Se6 octahedra,  a cornercorner with one Sm(1)Se6 octahedra,  a cornercorner with one Si(2)SiSe3 tetrahedra,  an edgeedge with one Na(4)Se6 octahedra,  an edgeedge with one Na(5)Se6 octahedra,  an edgeedge with one Na(6)Se6 octahedra,  an edgeedge with one Sm(1)Se6 octahedra, edges with three equivalent Na(2)Se6 octahedra, edges with three equivalent Na(3)Se6 octahedra, and  an edgeedge with one Si(2)SiSe3 tetrahedra. The corner-sharing octahedral tilt angles range from 5-8°. In the second Na site, Na(2) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), one Se(5), and one Se(6) atom to form NaSe6 octahedra that share  a cornercorner with one Na(4)Se6 octahedra,  a cornercorner with one Na(5)Se6 octahedra,  a cornercorner with one Na(6)Se6 octahedra,  a cornercorner with one Sm(1)Se6 octahedra,  a cornercorner with one Si(2)SiSe3 tetrahedra,  an edgeedge with one Na(4)Se6 octahedra,  an edgeedge with one Na(5)Se6 octahedra,  an edgeedge with one Na(6)Se6 octahedra,  an edgeedge with one Sm(1)Se6 octahedra, edges with three equivalent Na(1)Se6 octahedra, edges with three equivalent Na(3)Se6 octahedra, and  an edgeedge with one Si(2)SiSe3 tetrahedra. The corner-sharing octahedral tilt angles range from 6-9°. In the third Na site, Na(3) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), one Se(5), and one Se(6) atom to form NaSe6 octahedra that share  a cornercorner with one Na(4)Se6 octahedra,  a cornercorner with one Na(5)Se6 octahedra,  a cornercorner with one Na(6)Se6 octahedra,  a cornercorner with one Sm(1)Se6 octahedra,  a cornercorner with one Si(2)SiSe3 tetrahedra,  an edgeedge with one Na(4)Se6 octahedra,  an edgeedge with one Na(5)Se6 octahedra,  an edgeedge with one Na(6)Se6 octahedra,  an edgeedge with one Sm(1)Se6 octahedra, edges with three equivalent Na(1)Se6 octahedra, edges with three equivalent Na(2)Se6 octahedra, and  an edgeedge with one Si(2)SiSe3 tetrahedra. The corner-sharing octahedral tilt angles range from 7-8°. In the fourth Na site, Na(4) is bonded to two equivalent Se(2), two equivalent Se(3), and two equivalent Se(5) atoms to form NaSe6 octahedra that share corners with two equivalent Na(1)Se6 octahedra, corners with two equivalent Na(2)Se6 octahedra, corners with two equivalent Na(3)Se6 octahedra, corners with two equivalent Si(2)SiSe3 tetrahedra,  an edgeedge with one Na(6)Se6 octahedra, edges with two equivalent Na(1)Se6 octahedra, edges with two equivalent Na(2)Se6 octahedra, edges with two equivalent Na(3)Se6 octahedra, and edges with two equivalent Na(5)Se6 octahedra. The corner-sharing octahedral tilt angles range from 6-8°. In the fifth Na site, Na(5) is bonded to two equivalent Se(2), two equivalent Se(3), and two equivalent Se(6) atoms to form NaSe6 octahedra that share corners with two equivalent Na(1)Se6 octahedra, corners with two equivalent Na(2)Se6 octahedra, corners with two equivalent Na(3)Se6 octahedra, corners with four equivalent Si(2)SiSe3 tetrahedra,  an edgeedge with one Sm(1)Se6 octahedra, edges with two equivalent Na(1)Se6 octahedra, edges with two equivalent Na(2)Se6 octahedra, edges with two equivalent Na(3)Se6 octahedra, and edges with two equivalent Na(4)Se6 octahedra. The corner-sharing octahedral tilt angles range from 5-9°. In the sixth Na site, Na(6) is bonded to two equivalent Se(1), two equivalent Se(4), and two equivalent Se(5) atoms to form NaSe6 octahedra that share corners with two equivalent Na(1)Se6 octahedra, corners with two equivalent Na(2)Se6 octahedra, corners with two equivalent Na(3)Se6 octahedra, corners with two equivalent Si(2)SiSe3 tetrahedra,  an edgeedge with one Na(4)Se6 octahedra, edges with two equivalent Na(1)Se6 octahedra, edges with two equivalent Na(2)Se6 octahedra, edges with two equivalent Na(3)Se6 octahedra, and edges with two equivalent Sm(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 7-8°. Sm(1) is bonded to two equivalent Se(1), two equivalent Se(4), and two equivalent Se(6) atoms to form SmSe6 octahedra that share corners with two equivalent Na(1)Se6 octahedra, corners with two equivalent Na(2)Se6 octahedra, corners with two equivalent Na(3)Se6 octahedra, corners with four equivalent Si(2)SiSe3 tetrahedra,  an edgeedge with one Na(5)Se6 octahedra, edges with two equivalent Na(1)Se6 octahedra, edges with two equivalent Na(2)Se6 octahedra, edges with two equivalent Na(3)Se6 octahedra, and edges with two equivalent Na(6)Se6 octahedra. The corner-sharing octahedral tilt angles range from 7-8°. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a distorted trigonal non-coplanar geometry to one Se(1), one Se(3), and one Se(5) atom. In the second Si site, Si(2) is bonded to one Si(2), one Se(2), one Se(4), and one Se(6) atom to form distorted SiSiSe3 tetrahedra that share  a cornercorner with one Na(1)Se6 octahedra,  a cornercorner with one Na(2)Se6 octahedra,  a cornercorner with one Na(3)Se6 octahedra,  a cornercorner with one Na(4)Se6 octahedra,  a cornercorner with one Na(6)Se6 octahedra,  a cornercorner with one Se(4)Na4SmSi octahedra,  a cornercorner with one Se(6)Na4SmSi octahedra,  a cornercorner with one Se(2)Na5Si octahedra, corners with two equivalent Na(5)Se6 octahedra, corners with two equivalent Sm(1)Se6 octahedra,  an edgeedge with one Na(1)Se6 octahedra,  an edgeedge with one Na(2)Se6 octahedra, and  an edgeedge with one Na(3)Se6 octahedra. The corner-sharing octahedral tilt angles range from 18-78°. There are six inequivalent Se sites. In the first Se site, Se(5) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Na(6), and one Si(1) atom to form SeNa5Si octahedra that share  a cornercorner with one Se(4)Na4SmSi octahedra,  a cornercorner with one Se(6)Na4SmSi octahedra,  a cornercorner with one Se(2)Na5Si octahedra, corners with two equivalent Se(1)Na4SmSi octahedra, corners with two equivalent Se(3)Na5Si octahedra,  an edgeedge with one Se(6)Na4SmSi octahedra,  an edgeedge with one Se(5)Na5Si octahedra, edges with two equivalent Se(1)Na4SmSi octahedra, edges with two equivalent Se(4)Na4SmSi octahedra, edges with two equivalent Se(2)Na5Si octahedra, and edges with two equivalent Se(3)Na5Si octahedra. The corner-sharing octahedral tilt angles range from 3-89°. In the second Se site, Se(6) is bonded to one Na(1), one Na(2), one Na(3), one Na(5), one Sm(1), and one Si(2) atom to form distorted SeNa4SmSi octahedra that share  a cornercorner with one Se(1)Na4SmSi octahedra,  a cornercorner with one Se(3)Na5Si octahedra,  a cornercorner with one Se(5)Na5Si octahedra, corners with two equivalent Se(4)Na4SmSi octahedra, corners with two equivalent Se(2)Na5Si octahedra,  a cornercorner with one Si(2)SiSe3 tetrahedra,  an edgeedge with one Se(6)Na4SmSi octahedra,  an edgeedge with one Se(5)Na5Si octahedra, edges with two equivalent Se(1)Na4SmSi octahedra, edges with two equivalent Se(4)Na4SmSi octahedra, edges with two equivalent Se(2)Na5Si octahedra, and edges with two equivalent Se(3)Na5Si octahedra. The corner-sharing octahedral tilt angles range from 3-92°. In the third Se site, Se(1) is bonded to one Na(1), one Na(2), one Na(3), one Na(6), one Sm(1), and one Si(1) atom to form SeNa4SmSi octahedra that share  a cornercorner with one Se(4)Na4SmSi octahedra,  a cornercorner with one Se(6)Na4SmSi octahedra,  a cornercorner with one Se(2)Na5Si octahedra, corners with two equivalent Se(1)Na4SmSi octahedra, corners with two equivalent Se(5)Na5Si octahedra,  an edgeedge with one Se(2)Na5Si octahedra, edges with two equivalent Se(6)Na4SmSi octahedra, edges with two equivalent Se(3)Na5Si octahedra, edges with two equivalent Se(5)Na5Si octahedra, and edges with three equivalent Se(4)Na4SmSi octahedra. The corner-sharing octahedral tilt angles range from 1-91°. In the fourth Se site, Se(2) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Na(5), and one Si(2) atom to form SeNa5Si octahedra that share  a cornercorner with one Se(1)Na4SmSi octahedra,  a cornercorner with one Se(3)Na5Si octahedra,  a cornercorner with one Se(5)Na5Si octahedra, corners with two equivalent Se(6)Na4SmSi octahedra, corners with two equivalent Se(2)Na5Si octahedra,  a cornercorner with one Si(2)SiSe3 tetrahedra,  an edgeedge with one Se(1)Na4SmSi octahedra, edges with two equivalent Se(4)Na4SmSi octahedra, edges with two equivalent Se(6)Na4SmSi octahedra, edges with two equivalent Se(5)Na5Si octahedra, and edges with three equivalent Se(3)Na5Si octahedra. The corner-sharing octahedral tilt angles range from 1-92°. In the fifth Se site, Se(3) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Na(5), and one Si(1) atom to form SeNa5Si octahedra that share  a cornercorner with one Se(4)Na4SmSi octahedra,  a cornercorner with one Se(6)Na4SmSi octahedra,  a cornercorner with one Se(2)Na5Si octahedra, corners with two equivalent Se(3)Na5Si octahedra, corners with two equivalent Se(5)Na5Si octahedra,  an edgeedge with one Se(4)Na4SmSi octahedra, edges with two equivalent Se(1)Na4SmSi octahedra, edges with two equivalent Se(6)Na4SmSi octahedra, edges with two equivalent Se(5)Na5Si octahedra, and edges with three equivalent Se(2)Na5Si octahedra. The corner-sharing octahedral tilt angles range from 1-89°. In the sixth Se site, Se(4) is bonded to one Na(1), one Na(2), one Na(3), one Na(6), one Sm(1), and one Si(2) atom to form distorted SeNa4SmSi octahedra that share  a cornercorner with one Se(1)Na4SmSi octahedra,  a cornercorner with one Se(3)Na5Si octahedra,  a cornercorner with one Se(5)Na5Si octahedra, corners with two equivalent Se(4)Na4SmSi octahedra, corners with two equivalent Se(6)Na4SmSi octahedra,  a cornercorner with one Si(2)SiSe3 tetrahedra,  an edgeedge with one Se(3)Na5Si octahedra, edges with two equivalent Se(6)Na4SmSi octahedra, edges with two equivalent Se(2)Na5Si octahedra, edges with two equivalent Se(5)Na5Si octahedra, and edges with three equivalent Se(1)Na4SmSi octahedra. The corner-sharing octahedral tilt angles range from 3-93°. is represented by the CIF file [CIF]
data_Na9Sm(SiSe3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.858
_cell_length_b   9.858
_cell_length_c   7.071
_cell_angle_alpha   83.232
_cell_angle_beta   83.232
_cell_angle_gamma   76.619
_symmetry_Int_Tables_number   1
_cell_volume   660.928
_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  0.502  0.001  0.247  1.0
  Na  Na1  1  0.999  0.498  0.753  1.0
  Na  Na2  1  0.174  0.327  0.249  1.0
  Na  Na3  1  0.673  0.826  0.751  1.0
  Na  Na4  1  0.824  0.671  0.252  1.0
  Na  Na5  1  0.329  0.176  0.748  1.0
  Na  Na6  1  0.585  0.415  0.000  1.0
  Na  Na7  1  0.422  0.578  0.500  1.0
  Na  Na8  1  0.909  0.091  0.000  1.0
  Sm  Sm9  1  0.082  0.918  0.500  1.0
  Si  Si10  1  0.824  0.329  0.468  1.0
  Si  Si11  1  0.328  0.824  0.978  1.0
  Si  Si12  1  0.671  0.176  0.532  1.0
  Si  Si13  1  0.176  0.672  0.022  1.0
  Se  Se14  1  0.028  0.207  0.607  1.0
  Se  Se15  1  0.530  0.720  0.111  1.0
  Se  Se16  1  0.722  0.528  0.616  1.0
  Se  Se17  1  0.211  0.023  0.126  1.0
  Se  Se18  1  0.472  0.278  0.384  1.0
  Se  Se19  1  0.977  0.789  0.874  1.0
  Se  Se20  1  0.793  0.972  0.393  1.0
  Se  Se21  1  0.280  0.470  0.889  1.0
  Se  Se22  1  0.877  0.374  0.147  1.0
  Se  Se23  1  0.360  0.876  0.650  1.0
  Se  Se24  1  0.626  0.123  0.853  1.0
  Se  Se25  1  0.124  0.640  0.350  1.0
[/CIF]
.
The material described by Na9Sm(SiSe3)4 crystallizes in the monoclinic C2 space group. There are six inequivalent Na sites. In the first Na site, Na(1) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), one Se(5), and one Se(6) atom to form NaSe6 octahedra that share  a cornercorner with one Na(4)Se6 octahedra,  a cornercorner with one Na(5)Se6 octahedra,  a cornercorner with one Na(6)Se6 octahedra,  a cornercorner with one Sm(1)Se6 octahedra,  a cornercorner with one Si(2)SiSe3 tetrahedra,  an edgeedge with one Na(4)Se6 octahedra,  an edgeedge with one Na(5)Se6 octahedra,  an edgeedge with one Na(6)Se6 octahedra,  an edgeedge with one Sm(1)Se6 octahedra, edges with three equivalent Na(2)Se6 octahedra, edges with three equivalent Na(3)Se6 octahedra, and  an edgeedge with one Si(2)SiSe3 tetrahedra. The corner-sharing octahedral tilt angles range from 5-8°. In the second Na site, Na(2) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), one Se(5), and one Se(6) atom to form NaSe6 octahedra that share  a cornercorner with one Na(4)Se6 octahedra,  a cornercorner with one Na(5)Se6 octahedra,  a cornercorner with one Na(6)Se6 octahedra,  a cornercorner with one Sm(1)Se6 octahedra,  a cornercorner with one Si(2)SiSe3 tetrahedra,  an edgeedge with one Na(4)Se6 octahedra,  an edgeedge with one Na(5)Se6 octahedra,  an edgeedge with one Na(6)Se6 octahedra,  an edgeedge with one Sm(1)Se6 octahedra, edges with three equivalent Na(1)Se6 octahedra, edges with three equivalent Na(3)Se6 octahedra, and  an edgeedge with one Si(2)SiSe3 tetrahedra. The corner-sharing octahedral tilt angles range from 6-9°. In the third Na site, Na(3) is bonded to one Se(1), one Se(2), one Se(3), one Se(4), one Se(5), and one Se(6) atom to form NaSe6 octahedra that share  a cornercorner with one Na(4)Se6 octahedra,  a cornercorner with one Na(5)Se6 octahedra,  a cornercorner with one Na(6)Se6 octahedra,  a cornercorner with one Sm(1)Se6 octahedra,  a cornercorner with one Si(2)SiSe3 tetrahedra,  an edgeedge with one Na(4)Se6 octahedra,  an edgeedge with one Na(5)Se6 octahedra,  an edgeedge with one Na(6)Se6 octahedra,  an edgeedge with one Sm(1)Se6 octahedra, edges with three equivalent Na(1)Se6 octahedra, edges with three equivalent Na(2)Se6 octahedra, and  an edgeedge with one Si(2)SiSe3 tetrahedra. The corner-sharing octahedral tilt angles range from 7-8°. In the fourth Na site, Na(4) is bonded to two equivalent Se(2), two equivalent Se(3), and two equivalent Se(5) atoms to form NaSe6 octahedra that share corners with two equivalent Na(1)Se6 octahedra, corners with two equivalent Na(2)Se6 octahedra, corners with two equivalent Na(3)Se6 octahedra, corners with two equivalent Si(2)SiSe3 tetrahedra,  an edgeedge with one Na(6)Se6 octahedra, edges with two equivalent Na(1)Se6 octahedra, edges with two equivalent Na(2)Se6 octahedra, edges with two equivalent Na(3)Se6 octahedra, and edges with two equivalent Na(5)Se6 octahedra. The corner-sharing octahedral tilt angles range from 6-8°. In the fifth Na site, Na(5) is bonded to two equivalent Se(2), two equivalent Se(3), and two equivalent Se(6) atoms to form NaSe6 octahedra that share corners with two equivalent Na(1)Se6 octahedra, corners with two equivalent Na(2)Se6 octahedra, corners with two equivalent Na(3)Se6 octahedra, corners with four equivalent Si(2)SiSe3 tetrahedra,  an edgeedge with one Sm(1)Se6 octahedra, edges with two equivalent Na(1)Se6 octahedra, edges with two equivalent Na(2)Se6 octahedra, edges with two equivalent Na(3)Se6 octahedra, and edges with two equivalent Na(4)Se6 octahedra. The corner-sharing octahedral tilt angles range from 5-9°. In the sixth Na site, Na(6) is bonded to two equivalent Se(1), two equivalent Se(4), and two equivalent Se(5) atoms to form NaSe6 octahedra that share corners with two equivalent Na(1)Se6 octahedra, corners with two equivalent Na(2)Se6 octahedra, corners with two equivalent Na(3)Se6 octahedra, corners with two equivalent Si(2)SiSe3 tetrahedra,  an edgeedge with one Na(4)Se6 octahedra, edges with two equivalent Na(1)Se6 octahedra, edges with two equivalent Na(2)Se6 octahedra, edges with two equivalent Na(3)Se6 octahedra, and edges with two equivalent Sm(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 7-8°. Sm(1) is bonded to two equivalent Se(1), two equivalent Se(4), and two equivalent Se(6) atoms to form SmSe6 octahedra that share corners with two equivalent Na(1)Se6 octahedra, corners with two equivalent Na(2)Se6 octahedra, corners with two equivalent Na(3)Se6 octahedra, corners with four equivalent Si(2)SiSe3 tetrahedra,  an edgeedge with one Na(5)Se6 octahedra, edges with two equivalent Na(1)Se6 octahedra, edges with two equivalent Na(2)Se6 octahedra, edges with two equivalent Na(3)Se6 octahedra, and edges with two equivalent Na(6)Se6 octahedra. The corner-sharing octahedral tilt angles range from 7-8°. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a distorted trigonal non-coplanar geometry to one Se(1), one Se(3), and one Se(5) atom. In the second Si site, Si(2) is bonded to one Si(2), one Se(2), one Se(4), and one Se(6) atom to form distorted SiSiSe3 tetrahedra that share  a cornercorner with one Na(1)Se6 octahedra,  a cornercorner with one Na(2)Se6 octahedra,  a cornercorner with one Na(3)Se6 octahedra,  a cornercorner with one Na(4)Se6 octahedra,  a cornercorner with one Na(6)Se6 octahedra,  a cornercorner with one Se(4)Na4SmSi octahedra,  a cornercorner with one Se(6)Na4SmSi octahedra,  a cornercorner with one Se(2)Na5Si octahedra, corners with two equivalent Na(5)Se6 octahedra, corners with two equivalent Sm(1)Se6 octahedra,  an edgeedge with one Na(1)Se6 octahedra,  an edgeedge with one Na(2)Se6 octahedra, and  an edgeedge with one Na(3)Se6 octahedra. The corner-sharing octahedral tilt angles range from 18-78°. There are six inequivalent Se sites. In the first Se site, Se(5) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Na(6), and one Si(1) atom to form SeNa5Si octahedra that share  a cornercorner with one Se(4)Na4SmSi octahedra,  a cornercorner with one Se(6)Na4SmSi octahedra,  a cornercorner with one Se(2)Na5Si octahedra, corners with two equivalent Se(1)Na4SmSi octahedra, corners with two equivalent Se(3)Na5Si octahedra,  an edgeedge with one Se(6)Na4SmSi octahedra,  an edgeedge with one Se(5)Na5Si octahedra, edges with two equivalent Se(1)Na4SmSi octahedra, edges with two equivalent Se(4)Na4SmSi octahedra, edges with two equivalent Se(2)Na5Si octahedra, and edges with two equivalent Se(3)Na5Si octahedra. The corner-sharing octahedral tilt angles range from 3-89°. In the second Se site, Se(6) is bonded to one Na(1), one Na(2), one Na(3), one Na(5), one Sm(1), and one Si(2) atom to form distorted SeNa4SmSi octahedra that share  a cornercorner with one Se(1)Na4SmSi octahedra,  a cornercorner with one Se(3)Na5Si octahedra,  a cornercorner with one Se(5)Na5Si octahedra, corners with two equivalent Se(4)Na4SmSi octahedra, corners with two equivalent Se(2)Na5Si octahedra,  a cornercorner with one Si(2)SiSe3 tetrahedra,  an edgeedge with one Se(6)Na4SmSi octahedra,  an edgeedge with one Se(5)Na5Si octahedra, edges with two equivalent Se(1)Na4SmSi octahedra, edges with two equivalent Se(4)Na4SmSi octahedra, edges with two equivalent Se(2)Na5Si octahedra, and edges with two equivalent Se(3)Na5Si octahedra. The corner-sharing octahedral tilt angles range from 3-92°. In the third Se site, Se(1) is bonded to one Na(1), one Na(2), one Na(3), one Na(6), one Sm(1), and one Si(1) atom to form SeNa4SmSi octahedra that share  a cornercorner with one Se(4)Na4SmSi octahedra,  a cornercorner with one Se(6)Na4SmSi octahedra,  a cornercorner with one Se(2)Na5Si octahedra, corners with two equivalent Se(1)Na4SmSi octahedra, corners with two equivalent Se(5)Na5Si octahedra,  an edgeedge with one Se(2)Na5Si octahedra, edges with two equivalent Se(6)Na4SmSi octahedra, edges with two equivalent Se(3)Na5Si octahedra, edges with two equivalent Se(5)Na5Si octahedra, and edges with three equivalent Se(4)Na4SmSi octahedra. The corner-sharing octahedral tilt angles range from 1-91°. In the fourth Se site, Se(2) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Na(5), and one Si(2) atom to form SeNa5Si octahedra that share  a cornercorner with one Se(1)Na4SmSi octahedra,  a cornercorner with one Se(3)Na5Si octahedra,  a cornercorner with one Se(5)Na5Si octahedra, corners with two equivalent Se(6)Na4SmSi octahedra, corners with two equivalent Se(2)Na5Si octahedra,  a cornercorner with one Si(2)SiSe3 tetrahedra,  an edgeedge with one Se(1)Na4SmSi octahedra, edges with two equivalent Se(4)Na4SmSi octahedra, edges with two equivalent Se(6)Na4SmSi octahedra, edges with two equivalent Se(5)Na5Si octahedra, and edges with three equivalent Se(3)Na5Si octahedra. The corner-sharing octahedral tilt angles range from 1-92°. In the fifth Se site, Se(3) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Na(5), and one Si(1) atom to form SeNa5Si octahedra that share  a cornercorner with one Se(4)Na4SmSi octahedra,  a cornercorner with one Se(6)Na4SmSi octahedra,  a cornercorner with one Se(2)Na5Si octahedra, corners with two equivalent Se(3)Na5Si octahedra, corners with two equivalent Se(5)Na5Si octahedra,  an edgeedge with one Se(4)Na4SmSi octahedra, edges with two equivalent Se(1)Na4SmSi octahedra, edges with two equivalent Se(6)Na4SmSi octahedra, edges with two equivalent Se(5)Na5Si octahedra, and edges with three equivalent Se(2)Na5Si octahedra. The corner-sharing octahedral tilt angles range from 1-89°. In the sixth Se site, Se(4) is bonded to one Na(1), one Na(2), one Na(3), one Na(6), one Sm(1), and one Si(2) atom to form distorted SeNa4SmSi octahedra that share  a cornercorner with one Se(1)Na4SmSi octahedra,  a cornercorner with one Se(3)Na5Si octahedra,  a cornercorner with one Se(5)Na5Si octahedra, corners with two equivalent Se(4)Na4SmSi octahedra, corners with two equivalent Se(6)Na4SmSi octahedra,  a cornercorner with one Si(2)SiSe3 tetrahedra,  an edgeedge with one Se(3)Na5Si octahedra, edges with two equivalent Se(6)Na4SmSi octahedra, edges with two equivalent Se(2)Na5Si octahedra, edges with two equivalent Se(5)Na5Si octahedra, and edges with three equivalent Se(1)Na4SmSi octahedra. The corner-sharing octahedral tilt angles range from 3-93°. is represented by the CIF file [CIF]
data_Na9Sm(SiSe3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.858
_cell_length_b   9.858
_cell_length_c   7.071
_cell_angle_alpha   83.232
_cell_angle_beta   83.232
_cell_angle_gamma   76.619
_symmetry_Int_Tables_number   1
_cell_volume   660.928
_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  0.502  0.001  0.247  1.0
  Na  Na1  1  0.999  0.498  0.753  1.0
  Na  Na2  1  0.174  0.327  0.249  1.0
  Na  Na3  1  0.673  0.826  0.751  1.0
  Na  Na4  1  0.824  0.671  0.252  1.0
  Na  Na5  1  0.329  0.176  0.748  1.0
  Na  Na6  1  0.585  0.415  0.000  1.0
  Na  Na7  1  0.422  0.578  0.500  1.0
  Na  Na8  1  0.909  0.091  0.000  1.0
  Sm  Sm9  1  0.082  0.918  0.500  1.0
  Si  Si10  1  0.824  0.329  0.468  1.0
  Si  Si11  1  0.328  0.824  0.978  1.0
  Si  Si12  1  0.671  0.176  0.532  1.0
  Si  Si13  1  0.176  0.672  0.022  1.0
  Se  Se14  1  0.028  0.207  0.607  1.0
  Se  Se15  1  0.530  0.720  0.111  1.0
  Se  Se16  1  0.722  0.528  0.616  1.0
  Se  Se17  1  0.211  0.023  0.126  1.0
  Se  Se18  1  0.472  0.278  0.384  1.0
  Se  Se19  1  0.977  0.789  0.874  1.0
  Se  Se20  1  0.793  0.972  0.393  1.0
  Se  Se21  1  0.280  0.470  0.889  1.0
  Se  Se22  1  0.877  0.374  0.147  1.0
  Se  Se23  1  0.360  0.876  0.650  1.0
  Se  Se24  1  0.626  0.123  0.853  1.0
  Se  Se25  1  0.124  0.640  0.350  1.0
[/CIF]
.