The compound described by K4Pb2OBr8 crystallizes in the triclinic P-1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one O(1), two equivalent Br(1), two equivalent Br(2), and two equivalent Br(3) atoms. In the second K site, K(2) is bonded to two equivalent Br(1), two equivalent Br(2), and two equivalent Br(4) atoms to form distorted KBr6 pentagonal pyramids that share corners with two equivalent Pb(1)Br6 octahedra, corners with two equivalent Pb(2)Br6 octahedra, edges with two equivalent Pb(2)Br6 octahedra, and edges with three equivalent K(2)Br6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 48-69°. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded to two equivalent Br(1) and four equivalent Br(3) atoms to form PbBr6 octahedra that share corners with four equivalent K(2)Br6 pentagonal pyramids and edges with two equivalent Pb(1)Br6 octahedra. In the second Pb site, Pb(2) is bonded to two equivalent Br(2) and four equivalent Br(4) atoms to form PbBr6 octahedra that share corners with four equivalent K(2)Br6 pentagonal pyramids, edges with two equivalent Pb(2)Br6 octahedra, and edges with four equivalent K(2)Br6 pentagonal pyramids. O(1) is bonded in a linear geometry to two equivalent K(1) atoms. There are four inequivalent Br sites. In the first Br site, Br(1) is bonded to two equivalent K(1), two equivalent K(2), and one Pb(1) atom to form a mixture of distorted corner and edge-sharing BrK4Pb trigonal bipyramids. In the second Br site, Br(2) is bonded to two equivalent K(1), two equivalent K(2), and one Pb(2) atom to form a mixture of distorted corner and edge-sharing BrK4Pb trigonal bipyramids. In the third Br site, Br(3) is bonded in a rectangular see-saw-like geometry to two equivalent K(1) and two equivalent Pb(1) atoms. In the fourth Br site, Br(4) is bonded in a rectangular see-saw-like geometry to two equivalent K(2) and two equivalent Pb(2) atoms. is represented by the CIF file [CIF]
data_K4Pb2Br8O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.431
_cell_length_b   8.277
_cell_length_c   14.419
_cell_angle_alpha   90.386
_cell_angle_beta   89.628
_cell_angle_gamma   90.095
_symmetry_Int_Tables_number   1
_cell_volume   528.761
_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
  K  K0  1  0.466  0.086  0.331  1.0
  K  K1  1  0.520  0.413  0.827  1.0
  K  K2  1  0.534  0.914  0.669  1.0
  K  K3  1  0.480  0.587  0.173  1.0
  Pb  Pb4  1  0.000  0.500  0.500  1.0
  Pb  Pb5  1  0.000  0.000  0.000  1.0
  Br  Br6  1  0.984  0.386  0.302  1.0
  Br  Br7  1  0.021  0.119  0.802  1.0
  Br  Br8  1  0.016  0.614  0.698  1.0
  Br  Br9  1  0.979  0.881  0.198  1.0
  Br  Br10  1  0.496  0.748  0.457  1.0
  Br  Br11  1  0.506  0.749  0.959  1.0
  Br  Br12  1  0.504  0.252  0.543  1.0
  Br  Br13  1  0.494  0.251  0.041  1.0
  O  O14  1  0.000  0.000  0.500  1.0
[/CIF]
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The compound described by K4Pb2OBr8 crystallizes in the triclinic P-1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one O(1), two equivalent Br(1), two equivalent Br(2), and two equivalent Br(3) atoms. In the second K site, K(2) is bonded to two equivalent Br(1), two equivalent Br(2), and two equivalent Br(4) atoms to form distorted KBr6 pentagonal pyramids that share corners with two equivalent Pb(1)Br6 octahedra, corners with two equivalent Pb(2)Br6 octahedra, edges with two equivalent Pb(2)Br6 octahedra, and edges with three equivalent K(2)Br6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 48-69°. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded to two equivalent Br(1) and four equivalent Br(3) atoms to form PbBr6 octahedra that share corners with four equivalent K(2)Br6 pentagonal pyramids and edges with two equivalent Pb(1)Br6 octahedra. In the second Pb site, Pb(2) is bonded to two equivalent Br(2) and four equivalent Br(4) atoms to form PbBr6 octahedra that share corners with four equivalent K(2)Br6 pentagonal pyramids, edges with two equivalent Pb(2)Br6 octahedra, and edges with four equivalent K(2)Br6 pentagonal pyramids. O(1) is bonded in a linear geometry to two equivalent K(1) atoms. There are four inequivalent Br sites. In the first Br site, Br(1) is bonded to two equivalent K(1), two equivalent K(2), and one Pb(1) atom to form a mixture of distorted corner and edge-sharing BrK4Pb trigonal bipyramids. In the second Br site, Br(2) is bonded to two equivalent K(1), two equivalent K(2), and one Pb(2) atom to form a mixture of distorted corner and edge-sharing BrK4Pb trigonal bipyramids. In the third Br site, Br(3) is bonded in a rectangular see-saw-like geometry to two equivalent K(1) and two equivalent Pb(1) atoms. In the fourth Br site, Br(4) is bonded in a rectangular see-saw-like geometry to two equivalent K(2) and two equivalent Pb(2) atoms. is represented by the CIF file [CIF]
data_K4Pb2Br8O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.431
_cell_length_b   8.277
_cell_length_c   14.419
_cell_angle_alpha   90.386
_cell_angle_beta   89.628
_cell_angle_gamma   90.095
_symmetry_Int_Tables_number   1
_cell_volume   528.761
_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
  K  K0  1  0.466  0.086  0.331  1.0
  K  K1  1  0.520  0.413  0.827  1.0
  K  K2  1  0.534  0.914  0.669  1.0
  K  K3  1  0.480  0.587  0.173  1.0
  Pb  Pb4  1  0.000  0.500  0.500  1.0
  Pb  Pb5  1  0.000  0.000  0.000  1.0
  Br  Br6  1  0.984  0.386  0.302  1.0
  Br  Br7  1  0.021  0.119  0.802  1.0
  Br  Br8  1  0.016  0.614  0.698  1.0
  Br  Br9  1  0.979  0.881  0.198  1.0
  Br  Br10  1  0.496  0.748  0.457  1.0
  Br  Br11  1  0.506  0.749  0.959  1.0
  Br  Br12  1  0.504  0.252  0.543  1.0
  Br  Br13  1  0.494  0.251  0.041  1.0
  O  O14  1  0.000  0.000  0.500  1.0
[/CIF]
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