data_K2PBr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.74
_cell_length_b   4.74
_cell_length_c   6.89
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   K2PBr
_chemical_formula_sum   'K2 P1 Br1'
_cell_volume   154.74
_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  K1  1  0.0  0.0  0.44  1.0
  K  K2  1  0.37  0.37  0.0  1.0
  P  P3  1  0.0  0.0  0.0  1.0
  Br  Br0  1  0.37  0.37  0.44  1.0

data_K2PBr
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.7
_cell_length_b   6.7
_cell_length_c   6.89
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   K2PBr
_chemical_formula_sum   'K4 P2 Br2'
_cell_volume   309.47
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.44  1.0
  K  K1  2  0.37  0.0  0.0  1.0
  P  P2  2  0.0  0.0  0.0  1.0
  Br  Br3  2  0.37  0.0  0.44  1.0

K K P Br
K K P Br 0 3 o o o 1 2 o o o 
K2PBr crystallizes in the monoclinic Cm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 4-coordinate geometry to one P(1) and three equivalent Br(1) atoms. The K(1)-P(1) bond length is 3.06 Å. There is one shorter (2.48 Å) and two longer (3.46 Å) K(1)-Br(1) bond lengths. In the second K site, K(2) is bonded to three equivalent P(1) and two equivalent Br(1) atoms to form distorted corner-sharing KP3Br2 trigonal bipyramids. There is one shorter (2.48 Å) and two longer (3.46 Å) K(2)-P(1) bond lengths. There is one shorter (3.06 Å) and one longer (3.83 Å) K(2)-Br(1) bond length. P(1) is bonded in a 4-coordinate geometry to one K(1) and three equivalent K(2) atoms. Br(1) is bonded to two equivalent K(2) and three equivalent K(1) atoms to form distorted corner-sharing BrK5 trigonal bipyramids.