The structure described by NaPt2Se3 is Ilmenite-like structured and crystallizes in the hexagonal P6_3mc space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to three equivalent Pt(1) and three equivalent Se(1) atoms. In the second Na site, Na(2) is bonded to three equivalent Pt(1) and three equivalent Se(2) atoms to form distorted NaPt3Se3 pentagonal pyramids that share corners with three equivalent Pt(2)Se6 octahedra, corners with six equivalent Se(1)NaPt3 trigonal pyramids, edges with three equivalent Pt(1)Na2Se4 octahedra, and edges with three equivalent Se(2)NaPt3 trigonal pyramids. The corner-sharing octahedral tilt angles are 21°. There are two inequivalent Pt sites. In the first Pt site, Pt(1) is bonded to one Na(1), one Na(2), two equivalent Se(1), and two equivalent Se(2) atoms to form PtNa2Se4 octahedra that share corners with three equivalent Se(1)NaPt3 trigonal pyramids, corners with three equivalent Se(2)NaPt3 trigonal pyramids, edges with two equivalent Pt(2)Se6 octahedra, edges with four equivalent Pt(1)Na2Se4 octahedra, and  an edgeedge with one Na(2)Pt3Se3 pentagonal pyramid. In the second Pt site, Pt(2) is bonded to three equivalent Se(1) and three equivalent Se(2) atoms to form PtSe6 octahedra that share corners with three equivalent Na(2)Pt3Se3 pentagonal pyramids and edges with six equivalent Pt(1)Na2Se4 octahedra. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one Na(1), one Pt(2), and two equivalent Pt(1) atoms to form SeNaPt3 trigonal pyramids that share corners with three equivalent Pt(1)Na2Se4 octahedra, corners with two equivalent Na(2)Pt3Se3 pentagonal pyramids, corners with two equivalent Se(1)NaPt3 trigonal pyramids, corners with three equivalent Se(2)NaPt3 trigonal pyramids, edges with two equivalent Se(1)NaPt3 trigonal pyramids, and edges with two equivalent Se(2)NaPt3 trigonal pyramids. The corner-sharing octahedral tilt angles range from 1-73°. In the second Se site, Se(2) is bonded to one Na(2), one Pt(2), and two equivalent Pt(1) atoms to form SeNaPt3 trigonal pyramids that share corners with three equivalent Pt(1)Na2Se4 octahedra, corners with two equivalent Se(2)NaPt3 trigonal pyramids, corners with three equivalent Se(1)NaPt3 trigonal pyramids,  an edgeedge with one Na(2)Pt3Se3 pentagonal pyramid, edges with two equivalent Se(1)NaPt3 trigonal pyramids, and edges with two equivalent Se(2)NaPt3 trigonal pyramids. The corner-sharing octahedral tilt angles range from 40-86°. is represented by the CIF card [CIF]
data_NaPt2Se3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.423
_cell_length_b   7.423
_cell_length_c   11.518
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   549.614
_cell_formula_units_Z   4
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  0.333  0.667  0.315  1.0
  Na  Na1  1  0.667  0.333  0.815  1.0
  Na  Na2  1  1.000  0.000  0.692  1.0
  Na  Na3  1  0.000  1.000  0.192  1.0
  Pt  Pt4  1  0.834  0.166  0.006  1.0
  Pt  Pt5  1  0.668  0.834  0.506  1.0
  Pt  Pt6  1  0.166  0.332  0.506  1.0
  Pt  Pt7  1  0.834  0.668  0.006  1.0
  Pt  Pt8  1  0.332  0.166  0.006  1.0
  Pt  Pt9  1  0.166  0.834  0.506  1.0
  Pt  Pt10  1  0.667  0.333  0.499  1.0
  Pt  Pt11  1  0.333  0.667  0.999  1.0
  Se  Se12  1  0.499  0.501  0.612  1.0
  Se  Se13  1  0.998  0.499  0.112  1.0
  Se  Se14  1  0.501  0.002  0.112  1.0
  Se  Se15  1  0.499  0.998  0.612  1.0
  Se  Se16  1  0.160  0.840  0.895  1.0
  Se  Se17  1  0.320  0.160  0.395  1.0
  Se  Se18  1  0.840  0.680  0.395  1.0
  Se  Se19  1  0.160  0.320  0.895  1.0
  Se  Se20  1  0.680  0.840  0.895  1.0
  Se  Se21  1  0.840  0.160  0.395  1.0
  Se  Se22  1  0.501  0.499  0.112  1.0
  Se  Se23  1  0.002  0.501  0.612  1.0
[/CIF]
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The structure described by NaPt2Se3 is Ilmenite-like structured and crystallizes in the hexagonal P6_3mc space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to three equivalent Pt(1) and three equivalent Se(1) atoms. In the second Na site, Na(2) is bonded to three equivalent Pt(1) and three equivalent Se(2) atoms to form distorted NaPt3Se3 pentagonal pyramids that share corners with three equivalent Pt(2)Se6 octahedra, corners with six equivalent Se(1)NaPt3 trigonal pyramids, edges with three equivalent Pt(1)Na2Se4 octahedra, and edges with three equivalent Se(2)NaPt3 trigonal pyramids. The corner-sharing octahedral tilt angles are 21°. There are two inequivalent Pt sites. In the first Pt site, Pt(1) is bonded to one Na(1), one Na(2), two equivalent Se(1), and two equivalent Se(2) atoms to form PtNa2Se4 octahedra that share corners with three equivalent Se(1)NaPt3 trigonal pyramids, corners with three equivalent Se(2)NaPt3 trigonal pyramids, edges with two equivalent Pt(2)Se6 octahedra, edges with four equivalent Pt(1)Na2Se4 octahedra, and  an edgeedge with one Na(2)Pt3Se3 pentagonal pyramid. In the second Pt site, Pt(2) is bonded to three equivalent Se(1) and three equivalent Se(2) atoms to form PtSe6 octahedra that share corners with three equivalent Na(2)Pt3Se3 pentagonal pyramids and edges with six equivalent Pt(1)Na2Se4 octahedra. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one Na(1), one Pt(2), and two equivalent Pt(1) atoms to form SeNaPt3 trigonal pyramids that share corners with three equivalent Pt(1)Na2Se4 octahedra, corners with two equivalent Na(2)Pt3Se3 pentagonal pyramids, corners with two equivalent Se(1)NaPt3 trigonal pyramids, corners with three equivalent Se(2)NaPt3 trigonal pyramids, edges with two equivalent Se(1)NaPt3 trigonal pyramids, and edges with two equivalent Se(2)NaPt3 trigonal pyramids. The corner-sharing octahedral tilt angles range from 1-73°. In the second Se site, Se(2) is bonded to one Na(2), one Pt(2), and two equivalent Pt(1) atoms to form SeNaPt3 trigonal pyramids that share corners with three equivalent Pt(1)Na2Se4 octahedra, corners with two equivalent Se(2)NaPt3 trigonal pyramids, corners with three equivalent Se(1)NaPt3 trigonal pyramids,  an edgeedge with one Na(2)Pt3Se3 pentagonal pyramid, edges with two equivalent Se(1)NaPt3 trigonal pyramids, and edges with two equivalent Se(2)NaPt3 trigonal pyramids. The corner-sharing octahedral tilt angles range from 40-86°. is represented by the CIF card [CIF]
data_NaPt2Se3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.423
_cell_length_b   7.423
_cell_length_c   11.518
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   549.614
_cell_formula_units_Z   4
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  0.333  0.667  0.315  1.0
  Na  Na1  1  0.667  0.333  0.815  1.0
  Na  Na2  1  1.000  0.000  0.692  1.0
  Na  Na3  1  0.000  1.000  0.192  1.0
  Pt  Pt4  1  0.834  0.166  0.006  1.0
  Pt  Pt5  1  0.668  0.834  0.506  1.0
  Pt  Pt6  1  0.166  0.332  0.506  1.0
  Pt  Pt7  1  0.834  0.668  0.006  1.0
  Pt  Pt8  1  0.332  0.166  0.006  1.0
  Pt  Pt9  1  0.166  0.834  0.506  1.0
  Pt  Pt10  1  0.667  0.333  0.499  1.0
  Pt  Pt11  1  0.333  0.667  0.999  1.0
  Se  Se12  1  0.499  0.501  0.612  1.0
  Se  Se13  1  0.998  0.499  0.112  1.0
  Se  Se14  1  0.501  0.002  0.112  1.0
  Se  Se15  1  0.499  0.998  0.612  1.0
  Se  Se16  1  0.160  0.840  0.895  1.0
  Se  Se17  1  0.320  0.160  0.395  1.0
  Se  Se18  1  0.840  0.680  0.395  1.0
  Se  Se19  1  0.160  0.320  0.895  1.0
  Se  Se20  1  0.680  0.840  0.895  1.0
  Se  Se21  1  0.840  0.160  0.395  1.0
  Se  Se22  1  0.501  0.499  0.112  1.0
  Se  Se23  1  0.002  0.501  0.612  1.0
[/CIF]
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