The compound described by KH2PO4 crystallizes in the monoclinic P2/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent H(1), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. In the second K site, K(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form distorted KO6 pentagonal pyramids that share corners with four equivalent P(1)O4 tetrahedra and  an edgeedge with one P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with four equivalent K(2)O6 pentagonal pyramids. In the second P site, P(2) is bonded to two equivalent O(3) and two equivalent O(4) atoms to form PO4 tetrahedra that share  an edgeedge with one K(2)O6 pentagonal pyramid. There are two inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to one K(1) and one O(2) atom. In the second H site, H(2) is bonded in a linear geometry to one O(1) and one O(3) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one K(1), one K(2), one P(1), and one H(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one K(2), one P(1), and one H(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one K(1), one P(2), and one H(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one P(2) atom. is represented by the CIF card [CIF]
data_KP(HO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.368
_cell_length_b   7.543
_cell_length_c   10.309
_cell_angle_alpha   46.964
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   418.792
_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
  K  K0  1  0.967  0.500  0.250  1.0
  K  K1  1  0.662  0.000  0.250  1.0
  K  K2  1  0.338  0.000  0.750  1.0
  K  K3  1  0.033  0.500  0.750  1.0
  P  P4  1  0.426  0.500  0.250  1.0
  P  P5  1  0.107  0.000  0.250  1.0
  P  P6  1  0.893  0.000  0.750  1.0
  P  P7  1  0.574  0.500  0.750  1.0
  H  H8  1  0.628  0.766  0.055  1.0
  H  H9  1  0.277  0.334  0.105  1.0
  H  H10  1  0.277  0.666  0.395  1.0
  H  H11  1  0.628  0.234  0.445  1.0
  H  H12  1  0.372  0.766  0.555  1.0
  H  H13  1  0.723  0.334  0.605  1.0
  H  H14  1  0.723  0.666  0.895  1.0
  H  H15  1  0.372  0.234  0.945  1.0
  O  O16  1  0.320  0.529  0.110  1.0
  O  O17  1  0.559  0.729  0.155  1.0
  O  O18  1  0.248  0.211  0.094  1.0
  O  O19  1  0.004  0.904  0.184  1.0
  O  O20  1  0.559  0.271  0.345  1.0
  O  O21  1  0.320  0.471  0.390  1.0
  O  O22  1  0.004  0.096  0.316  1.0
  O  O23  1  0.248  0.789  0.406  1.0
  O  O24  1  0.752  0.211  0.594  1.0
  O  O25  1  0.996  0.904  0.684  1.0
  O  O26  1  0.680  0.529  0.610  1.0
  O  O27  1  0.441  0.729  0.655  1.0
  O  O28  1  0.996  0.096  0.816  1.0
  O  O29  1  0.752  0.789  0.906  1.0
  O  O30  1  0.441  0.271  0.845  1.0
  O  O31  1  0.680  0.471  0.890  1.0
[/CIF]
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The compound described by KH2PO4 crystallizes in the monoclinic P2/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent H(1), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. In the second K site, K(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form distorted KO6 pentagonal pyramids that share corners with four equivalent P(1)O4 tetrahedra and  an edgeedge with one P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with four equivalent K(2)O6 pentagonal pyramids. In the second P site, P(2) is bonded to two equivalent O(3) and two equivalent O(4) atoms to form PO4 tetrahedra that share  an edgeedge with one K(2)O6 pentagonal pyramid. There are two inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to one K(1) and one O(2) atom. In the second H site, H(2) is bonded in a linear geometry to one O(1) and one O(3) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one K(1), one K(2), one P(1), and one H(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one K(2), one P(1), and one H(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one K(1), one P(2), and one H(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one P(2) atom. is represented by the CIF card [CIF]
data_KP(HO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.368
_cell_length_b   7.543
_cell_length_c   10.309
_cell_angle_alpha   46.964
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   418.792
_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
  K  K0  1  0.967  0.500  0.250  1.0
  K  K1  1  0.662  0.000  0.250  1.0
  K  K2  1  0.338  0.000  0.750  1.0
  K  K3  1  0.033  0.500  0.750  1.0
  P  P4  1  0.426  0.500  0.250  1.0
  P  P5  1  0.107  0.000  0.250  1.0
  P  P6  1  0.893  0.000  0.750  1.0
  P  P7  1  0.574  0.500  0.750  1.0
  H  H8  1  0.628  0.766  0.055  1.0
  H  H9  1  0.277  0.334  0.105  1.0
  H  H10  1  0.277  0.666  0.395  1.0
  H  H11  1  0.628  0.234  0.445  1.0
  H  H12  1  0.372  0.766  0.555  1.0
  H  H13  1  0.723  0.334  0.605  1.0
  H  H14  1  0.723  0.666  0.895  1.0
  H  H15  1  0.372  0.234  0.945  1.0
  O  O16  1  0.320  0.529  0.110  1.0
  O  O17  1  0.559  0.729  0.155  1.0
  O  O18  1  0.248  0.211  0.094  1.0
  O  O19  1  0.004  0.904  0.184  1.0
  O  O20  1  0.559  0.271  0.345  1.0
  O  O21  1  0.320  0.471  0.390  1.0
  O  O22  1  0.004  0.096  0.316  1.0
  O  O23  1  0.248  0.789  0.406  1.0
  O  O24  1  0.752  0.211  0.594  1.0
  O  O25  1  0.996  0.904  0.684  1.0
  O  O26  1  0.680  0.529  0.610  1.0
  O  O27  1  0.441  0.729  0.655  1.0
  O  O28  1  0.996  0.096  0.816  1.0
  O  O29  1  0.752  0.789  0.906  1.0
  O  O30  1  0.441  0.271  0.845  1.0
  O  O31  1  0.680  0.471  0.890  1.0
[/CIF]
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