The material described by Na4Eu(SiSe3)2 crystallizes in the monoclinic C2 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form NaSe6 octahedra that share corners with two equivalent Na(4)Se6 octahedra, corners with two equivalent Eu(1)Se6 octahedra, corners with two equivalent Si(1)SiSe3 tetrahedra, edges with two equivalent Na(4)Se6 octahedra, edges with two equivalent Eu(1)Se6 octahedra, edges with three equivalent Na(2)Se6 octahedra, edges with three equivalent Na(3)Se6 octahedra, and edges with two equivalent Si(1)SiSe3 tetrahedra. The corner-sharing octahedral tilt angles range from 7-8°. In the second Na site, Na(2) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form NaSe6 octahedra that share corners with two equivalent Na(4)Se6 octahedra, corners with two equivalent Eu(1)Se6 octahedra, corners with two equivalent Si(1)SiSe3 tetrahedra, edges with two equivalent Na(4)Se6 octahedra, edges with two equivalent Eu(1)Se6 octahedra, edges with three equivalent Na(1)Se6 octahedra, edges with three equivalent Na(3)Se6 octahedra, and edges with two equivalent Si(1)SiSe3 tetrahedra. The corner-sharing octahedral tilt angles range from 7-8°. In the third Na site, Na(3) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form NaSe6 octahedra that share corners with two equivalent Na(4)Se6 octahedra, corners with two equivalent Eu(1)Se6 octahedra, corners with two equivalent Si(1)SiSe3 tetrahedra, edges with two equivalent Na(4)Se6 octahedra, edges with two equivalent Eu(1)Se6 octahedra, edges with three equivalent Na(1)Se6 octahedra, edges with three equivalent Na(2)Se6 octahedra, and edges with two equivalent Si(1)SiSe3 tetrahedra. The corner-sharing octahedral tilt angles are 7°. In the fourth Na site, Na(4) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) 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 six equivalent Si(1)SiSe3 tetrahedra, 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 three equivalent Eu(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 7-8°. Eu(1) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form EuSe6 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 six equivalent Si(1)SiSe3 tetrahedra, 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 three equivalent Na(4)Se6 octahedra. The corner-sharing octahedral tilt angles range from 7-8°. Si(1) is bonded to one Si(1), one Se(1), one Se(2), and one Se(3) 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 Se(1)Na4EuSi octahedra,  a cornercorner with one Se(2)Na4EuSi octahedra,  a cornercorner with one Se(3)Na4EuSi octahedra, corners with three equivalent Na(4)Se6 octahedra, corners with three equivalent Eu(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 20-77°. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Eu(1), and one Si(1) atom to form SeNa4EuSi octahedra that share  a cornercorner with one Se(1)Na4EuSi octahedra, corners with three equivalent Se(2)Na4EuSi octahedra, corners with three equivalent Se(3)Na4EuSi octahedra,  a cornercorner with one Si(1)SiSe3 tetrahedra, edges with two equivalent Se(1)Na4EuSi octahedra, edges with four equivalent Se(2)Na4EuSi octahedra, and edges with four equivalent Se(3)Na4EuSi octahedra. The corner-sharing octahedral tilt angles range from 0-91°. In the second Se site, Se(2) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Eu(1), and one Si(1) atom to form SeNa4EuSi octahedra that share  a cornercorner with one Se(3)Na4EuSi octahedra, corners with three equivalent Se(1)Na4EuSi octahedra, corners with three equivalent Se(2)Na4EuSi octahedra,  a cornercorner with one Si(1)SiSe3 tetrahedra,  an edgeedge with one Se(2)Na4EuSi octahedra, edges with four equivalent Se(1)Na4EuSi octahedra, and edges with five equivalent Se(3)Na4EuSi octahedra. The corner-sharing octahedral tilt angles range from 0-91°. In the third Se site, Se(3) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Eu(1), and one Si(1) atom to form SeNa4EuSi octahedra that share  a cornercorner with one Se(2)Na4EuSi octahedra, corners with three equivalent Se(1)Na4EuSi octahedra, corners with three equivalent Se(3)Na4EuSi octahedra,  a cornercorner with one Si(1)SiSe3 tetrahedra,  an edgeedge with one Se(3)Na4EuSi octahedra, edges with four equivalent Se(1)Na4EuSi octahedra, and edges with five equivalent Se(2)Na4EuSi octahedra. The corner-sharing octahedral tilt angles range from 0-91°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na4Eu(SiSe3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.132
_cell_length_b   7.132
_cell_length_c   8.011
_cell_angle_alpha   81.373
_cell_angle_beta   81.373
_cell_angle_gamma   119.811
_symmetry_Int_Tables_number   1
_cell_volume   337.406
_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  0.827  0.173  0.000  1.0
  Na  Na1  1  0.173  0.827  0.000  1.0
  Na  Na2  1  0.500  0.500  0.000  1.0
  Na  Na3  1  0.666  0.334  0.500  1.0
  Eu  Eu4  1  0.334  0.666  0.500  1.0
  Si  Si5  1  0.050  0.050  0.346  1.0
  Si  Si6  1  0.950  0.950  0.654  1.0
  Se  Se7  1  0.774  0.774  0.255  1.0
  Se  Se8  1  0.226  0.226  0.745  1.0
  Se  Se9  1  0.082  0.390  0.254  1.0
  Se  Se10  1  0.389  0.080  0.254  1.0
  Se  Se11  1  0.920  0.611  0.746  1.0
  Se  Se12  1  0.610  0.918  0.746  1.0
[/CIF]
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The material described by Na4Eu(SiSe3)2 crystallizes in the monoclinic C2 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form NaSe6 octahedra that share corners with two equivalent Na(4)Se6 octahedra, corners with two equivalent Eu(1)Se6 octahedra, corners with two equivalent Si(1)SiSe3 tetrahedra, edges with two equivalent Na(4)Se6 octahedra, edges with two equivalent Eu(1)Se6 octahedra, edges with three equivalent Na(2)Se6 octahedra, edges with three equivalent Na(3)Se6 octahedra, and edges with two equivalent Si(1)SiSe3 tetrahedra. The corner-sharing octahedral tilt angles range from 7-8°. In the second Na site, Na(2) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form NaSe6 octahedra that share corners with two equivalent Na(4)Se6 octahedra, corners with two equivalent Eu(1)Se6 octahedra, corners with two equivalent Si(1)SiSe3 tetrahedra, edges with two equivalent Na(4)Se6 octahedra, edges with two equivalent Eu(1)Se6 octahedra, edges with three equivalent Na(1)Se6 octahedra, edges with three equivalent Na(3)Se6 octahedra, and edges with two equivalent Si(1)SiSe3 tetrahedra. The corner-sharing octahedral tilt angles range from 7-8°. In the third Na site, Na(3) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form NaSe6 octahedra that share corners with two equivalent Na(4)Se6 octahedra, corners with two equivalent Eu(1)Se6 octahedra, corners with two equivalent Si(1)SiSe3 tetrahedra, edges with two equivalent Na(4)Se6 octahedra, edges with two equivalent Eu(1)Se6 octahedra, edges with three equivalent Na(1)Se6 octahedra, edges with three equivalent Na(2)Se6 octahedra, and edges with two equivalent Si(1)SiSe3 tetrahedra. The corner-sharing octahedral tilt angles are 7°. In the fourth Na site, Na(4) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) 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 six equivalent Si(1)SiSe3 tetrahedra, 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 three equivalent Eu(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 7-8°. Eu(1) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form EuSe6 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 six equivalent Si(1)SiSe3 tetrahedra, 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 three equivalent Na(4)Se6 octahedra. The corner-sharing octahedral tilt angles range from 7-8°. Si(1) is bonded to one Si(1), one Se(1), one Se(2), and one Se(3) 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 Se(1)Na4EuSi octahedra,  a cornercorner with one Se(2)Na4EuSi octahedra,  a cornercorner with one Se(3)Na4EuSi octahedra, corners with three equivalent Na(4)Se6 octahedra, corners with three equivalent Eu(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 20-77°. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Eu(1), and one Si(1) atom to form SeNa4EuSi octahedra that share  a cornercorner with one Se(1)Na4EuSi octahedra, corners with three equivalent Se(2)Na4EuSi octahedra, corners with three equivalent Se(3)Na4EuSi octahedra,  a cornercorner with one Si(1)SiSe3 tetrahedra, edges with two equivalent Se(1)Na4EuSi octahedra, edges with four equivalent Se(2)Na4EuSi octahedra, and edges with four equivalent Se(3)Na4EuSi octahedra. The corner-sharing octahedral tilt angles range from 0-91°. In the second Se site, Se(2) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Eu(1), and one Si(1) atom to form SeNa4EuSi octahedra that share  a cornercorner with one Se(3)Na4EuSi octahedra, corners with three equivalent Se(1)Na4EuSi octahedra, corners with three equivalent Se(2)Na4EuSi octahedra,  a cornercorner with one Si(1)SiSe3 tetrahedra,  an edgeedge with one Se(2)Na4EuSi octahedra, edges with four equivalent Se(1)Na4EuSi octahedra, and edges with five equivalent Se(3)Na4EuSi octahedra. The corner-sharing octahedral tilt angles range from 0-91°. In the third Se site, Se(3) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Eu(1), and one Si(1) atom to form SeNa4EuSi octahedra that share  a cornercorner with one Se(2)Na4EuSi octahedra, corners with three equivalent Se(1)Na4EuSi octahedra, corners with three equivalent Se(3)Na4EuSi octahedra,  a cornercorner with one Si(1)SiSe3 tetrahedra,  an edgeedge with one Se(3)Na4EuSi octahedra, edges with four equivalent Se(1)Na4EuSi octahedra, and edges with five equivalent Se(2)Na4EuSi octahedra. The corner-sharing octahedral tilt angles range from 0-91°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na4Eu(SiSe3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.132
_cell_length_b   7.132
_cell_length_c   8.011
_cell_angle_alpha   81.373
_cell_angle_beta   81.373
_cell_angle_gamma   119.811
_symmetry_Int_Tables_number   1
_cell_volume   337.406
_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  0.827  0.173  0.000  1.0
  Na  Na1  1  0.173  0.827  0.000  1.0
  Na  Na2  1  0.500  0.500  0.000  1.0
  Na  Na3  1  0.666  0.334  0.500  1.0
  Eu  Eu4  1  0.334  0.666  0.500  1.0
  Si  Si5  1  0.050  0.050  0.346  1.0
  Si  Si6  1  0.950  0.950  0.654  1.0
  Se  Se7  1  0.774  0.774  0.255  1.0
  Se  Se8  1  0.226  0.226  0.745  1.0
  Se  Se9  1  0.082  0.390  0.254  1.0
  Se  Se10  1  0.389  0.080  0.254  1.0
  Se  Se11  1  0.920  0.611  0.746  1.0
  Se  Se12  1  0.610  0.918  0.746  1.0
[/CIF]
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