The material described by KPt2Se3 is Ilmenite-like structured and crystallizes in the trigonal R-3m space group. K(1) is bonded in a 6-coordinate geometry to three equivalent Pt(2) and three equivalent Se(1) atoms. There are two inequivalent Pt sites. In the first Pt site, Pt(1) is bonded to six equivalent Se(1) atoms to form edge-sharing PtSe6 octahedra. In the second Pt site, Pt(2) is bonded to two equivalent K(1) and four equivalent Se(1) atoms to form PtK2Se4 octahedra that share corners with six equivalent Se(1)KPt3 trigonal pyramids, edges with two equivalent Pt(1)Se6 octahedra, and edges with four equivalent Pt(2)K2Se4 octahedra. Se(1) is bonded to one K(1), one Pt(1), and two equivalent Pt(2) atoms to form distorted SeKPt3 trigonal pyramids that share corners with three equivalent Pt(2)K2Se4 octahedra, corners with five equivalent Se(1)KPt3 trigonal pyramids, and edges with four equivalent Se(1)KPt3 trigonal pyramids. The corner-sharing octahedral tilt angles range from 37-79°. is represented by the CIF card [CIF]
data_KPt2Se3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.787
_cell_length_b   7.787
_cell_length_c   7.787
_cell_angle_alpha   56.971
_cell_angle_beta   56.971
_cell_angle_gamma   56.971
_symmetry_Int_Tables_number   1
_cell_volume   310.592
_cell_formula_units_Z   2
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
  K  K0  1  0.200  0.200  0.200  1.0
  K  K1  1  0.800  0.800  0.800  1.0
  Pt  Pt2  1  0.000  0.000  0.000  1.0
  Pt  Pt3  1  0.500  0.000  0.500  1.0
  Pt  Pt4  1  0.000  0.500  0.500  1.0
  Pt  Pt5  1  0.500  0.500  0.000  1.0
  Se  Se6  1  0.765  0.765  0.277  1.0
  Se  Se7  1  0.235  0.723  0.235  1.0
  Se  Se8  1  0.765  0.277  0.765  1.0
  Se  Se9  1  0.277  0.765  0.765  1.0
  Se  Se10  1  0.235  0.235  0.723  1.0
  Se  Se11  1  0.723  0.235  0.235  1.0
[/CIF]
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The material described by KPt2Se3 is Ilmenite-like structured and crystallizes in the trigonal R-3m space group. K(1) is bonded in a 6-coordinate geometry to three equivalent Pt(2) and three equivalent Se(1) atoms. There are two inequivalent Pt sites. In the first Pt site, Pt(1) is bonded to six equivalent Se(1) atoms to form edge-sharing PtSe6 octahedra. In the second Pt site, Pt(2) is bonded to two equivalent K(1) and four equivalent Se(1) atoms to form PtK2Se4 octahedra that share corners with six equivalent Se(1)KPt3 trigonal pyramids, edges with two equivalent Pt(1)Se6 octahedra, and edges with four equivalent Pt(2)K2Se4 octahedra. Se(1) is bonded to one K(1), one Pt(1), and two equivalent Pt(2) atoms to form distorted SeKPt3 trigonal pyramids that share corners with three equivalent Pt(2)K2Se4 octahedra, corners with five equivalent Se(1)KPt3 trigonal pyramids, and edges with four equivalent Se(1)KPt3 trigonal pyramids. The corner-sharing octahedral tilt angles range from 37-79°. is represented by the CIF card [CIF]
data_KPt2Se3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.787
_cell_length_b   7.787
_cell_length_c   7.787
_cell_angle_alpha   56.971
_cell_angle_beta   56.971
_cell_angle_gamma   56.971
_symmetry_Int_Tables_number   1
_cell_volume   310.592
_cell_formula_units_Z   2
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
  K  K0  1  0.200  0.200  0.200  1.0
  K  K1  1  0.800  0.800  0.800  1.0
  Pt  Pt2  1  0.000  0.000  0.000  1.0
  Pt  Pt3  1  0.500  0.000  0.500  1.0
  Pt  Pt4  1  0.000  0.500  0.500  1.0
  Pt  Pt5  1  0.500  0.500  0.000  1.0
  Se  Se6  1  0.765  0.765  0.277  1.0
  Se  Se7  1  0.235  0.723  0.235  1.0
  Se  Se8  1  0.765  0.277  0.765  1.0
  Se  Se9  1  0.277  0.765  0.765  1.0
  Se  Se10  1  0.235  0.235  0.723  1.0
  Se  Se11  1  0.723  0.235  0.235  1.0
[/CIF]
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