The structure described by KAlP4(H2O7)2 crystallizes in the triclinic P-1 space group. K(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms. Al(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form AlO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra and corners with four equivalent P(1)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-43°. In the second P site, P(2) is bonded to one O(1), one O(2), one O(4), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Al(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. There are two inequivalent H sites. In the first H site, H(1) is bonded in a distorted linear geometry to one O(1) and one O(6) atom. In the second H site, H(2) is bonded in a distorted linear geometry to one O(1) and one O(7) atom. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one P(2), one H(1), and one H(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one K(1), one Al(1), and one P(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(1), one Al(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Al(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one K(1), one P(1), and one H(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one K(1), one P(2), and one H(2) atom. is represented by the CIF file [CIF]
data_KAlP4(H2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.956
_cell_length_b   7.558
_cell_length_c   7.870
_cell_angle_alpha   81.682
_cell_angle_beta   83.658
_cell_angle_gamma   73.918
_symmetry_Int_Tables_number   1
_cell_volume   279.508
_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  0.000  0.000  0.000  1.0
  Al  Al1  1  0.000  0.500  0.000  1.0
  P  P2  1  0.419  0.605  0.225  1.0
  P  P3  1  0.581  0.395  0.775  1.0
  P  P4  1  0.313  0.236  0.316  1.0
  P  P5  1  0.687  0.764  0.684  1.0
  H  H6  1  0.128  0.782  0.411  1.0
  H  H7  1  0.872  0.218  0.589  1.0
  H  H8  1  0.314  0.998  0.622  1.0
  H  H9  1  0.686  0.002  0.378  1.0
  O  O10  1  0.166  0.165  0.478  1.0
  O  O11  1  0.834  0.835  0.522  1.0
  O  O12  1  0.162  0.280  0.151  1.0
  O  O13  1  0.838  0.720  0.849  1.0
  O  O14  1  0.240  0.628  0.074  1.0
  O  O15  1  0.760  0.372  0.926  1.0
  O  O16  1  0.379  0.426  0.354  1.0
  O  O17  1  0.621  0.574  0.646  1.0
  O  O18  1  0.272  0.412  0.822  1.0
  O  O19  1  0.728  0.588  0.178  1.0
  O  O20  1  0.308  0.773  0.332  1.0
  O  O21  1  0.692  0.227  0.668  1.0
  O  O22  1  0.390  0.903  0.722  1.0
  O  O23  1  0.610  0.097  0.278  1.0
[/CIF]
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The structure described by KAlP4(H2O7)2 crystallizes in the triclinic P-1 space group. K(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms. Al(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form AlO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra and corners with four equivalent P(1)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-43°. In the second P site, P(2) is bonded to one O(1), one O(2), one O(4), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Al(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. There are two inequivalent H sites. In the first H site, H(1) is bonded in a distorted linear geometry to one O(1) and one O(6) atom. In the second H site, H(2) is bonded in a distorted linear geometry to one O(1) and one O(7) atom. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one P(2), one H(1), and one H(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one K(1), one Al(1), and one P(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(1), one Al(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Al(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one K(1), one P(1), and one H(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one K(1), one P(2), and one H(2) atom. is represented by the CIF file [CIF]
data_KAlP4(H2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.956
_cell_length_b   7.558
_cell_length_c   7.870
_cell_angle_alpha   81.682
_cell_angle_beta   83.658
_cell_angle_gamma   73.918
_symmetry_Int_Tables_number   1
_cell_volume   279.508
_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  0.000  0.000  0.000  1.0
  Al  Al1  1  0.000  0.500  0.000  1.0
  P  P2  1  0.419  0.605  0.225  1.0
  P  P3  1  0.581  0.395  0.775  1.0
  P  P4  1  0.313  0.236  0.316  1.0
  P  P5  1  0.687  0.764  0.684  1.0
  H  H6  1  0.128  0.782  0.411  1.0
  H  H7  1  0.872  0.218  0.589  1.0
  H  H8  1  0.314  0.998  0.622  1.0
  H  H9  1  0.686  0.002  0.378  1.0
  O  O10  1  0.166  0.165  0.478  1.0
  O  O11  1  0.834  0.835  0.522  1.0
  O  O12  1  0.162  0.280  0.151  1.0
  O  O13  1  0.838  0.720  0.849  1.0
  O  O14  1  0.240  0.628  0.074  1.0
  O  O15  1  0.760  0.372  0.926  1.0
  O  O16  1  0.379  0.426  0.354  1.0
  O  O17  1  0.621  0.574  0.646  1.0
  O  O18  1  0.272  0.412  0.822  1.0
  O  O19  1  0.728  0.588  0.178  1.0
  O  O20  1  0.308  0.773  0.332  1.0
  O  O21  1  0.692  0.227  0.668  1.0
  O  O22  1  0.390  0.903  0.722  1.0
  O  O23  1  0.610  0.097  0.278  1.0
[/CIF]
.