The structure described by NH4Fe(HPO4)2 crystallizes in the triclinic P-1 space group. The structure consists of two ammonium molecules inside a Fe3P6NH10O24 framework. In the Fe3P6NH10O24 framework, there are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(9) atoms to form FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(1), one O(11), one O(4), one O(5), one O(6), and one O(8) atom to form FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. There are three inequivalent P sites. In the first P site, P(1) is bonded to one O(10), one O(2), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra and corners with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 15-56°. In the second P site, P(2) is bonded to one O(11), one O(12), one O(3), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra and corners with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 33-55°. In the third P site, P(3) is bonded to one O(1), one O(4), one O(7), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra and corners with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-49°. N(2) is bonded in a square co-planar geometry to two equivalent H(8) and two equivalent H(9) atoms. There are five inequivalent H sites. In the first H site, H(4) is bonded in a distorted single-bond geometry to one O(6) and one O(7) atom. In the second H site, H(6) is bonded in a distorted linear geometry to one O(1) and one O(12) atom. In the third H site, H(7) is bonded in a distorted linear geometry to one O(10) and one O(9) atom. In the fourth H site, H(8) is bonded in a linear geometry to one N(2) and one O(5) atom. In the fifth H site, H(9) is bonded in a single-bond geometry to one N(2) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Fe(2), one P(3), and one H(6) atom. In the second O site, O(2) is bonded in a linear geometry to one Fe(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Fe(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(3) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Fe(2), one P(1), and one H(8) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Fe(2), one P(1), and one H(4) atom. In the seventh O site, O(7) is bonded in a distorted water-like geometry to one P(3) and one H(4) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Fe(2) and one P(2) atom. In the ninth O site, O(9) is bonded in a distorted trigonal non-coplanar geometry to one Fe(1), one P(3), and one H(7) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one P(1) and one H(7) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the twelfth O site, O(12) is bonded in a water-like geometry to one P(2) and one H(6) atom. is represented by the CIF file [CIF]
data_FeP2H6NO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.216
_cell_length_b   8.831
_cell_length_c   9.637
_cell_angle_alpha   64.238
_cell_angle_beta   70.216
_cell_angle_gamma   70.024
_symmetry_Int_Tables_number   1
_cell_volume   506.534
_cell_formula_units_Z   3
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
  Fe  Fe0  1  0.500  0.500  0.500  1.0
  Fe  Fe1  1  0.297  0.280  0.051  1.0
  Fe  Fe2  1  0.703  0.720  0.949  1.0
  P  P3  1  0.956  0.561  0.219  1.0
  P  P4  1  0.044  0.439  0.781  1.0
  P  P5  1  0.410  0.874  0.236  1.0
  P  P6  1  0.590  0.126  0.764  1.0
  P  P7  1  0.590  0.344  0.221  1.0
  P  P8  1  0.410  0.656  0.779  1.0
  H  H9  1  0.802  0.785  0.431  1.0
  H  H10  1  0.198  0.215  0.569  1.0
  H  H11  1  0.154  0.203  0.413  1.0
  H  H12  1  0.846  0.797  0.587  1.0
  H  H13  1  0.965  0.206  0.573  1.0
  H  H14  1  0.035  0.794  0.427  1.0
  H  H15  1  0.106  0.739  0.742  1.0
  H  H16  1  0.894  0.261  0.258  1.0
  H  H17  1  0.162  0.029  0.588  1.0
  H  H18  1  0.838  0.971  0.412  1.0
  H  H19  1  0.425  0.961  0.771  1.0
  H  H20  1  0.575  0.039  0.229  1.0
  H  H21  1  0.765  0.461  0.708  1.0
  H  H22  1  0.235  0.539  0.292  1.0
  H  H23  1  0.042  0.127  0.975  1.0
  H  H24  1  0.958  0.873  0.025  1.0
  H  H25  1  0.887  0.071  0.940  1.0
  H  H26  1  0.113  0.929  0.060  1.0
  N  N27  1  0.120  0.163  0.535  1.0
  N  N28  1  0.880  0.837  0.465  1.0
  N  N29  1  0.000  0.000  0.000  1.0
  O  O30  1  0.516  0.759  0.811  1.0
  O  O31  1  0.484  0.241  0.189  1.0
  O  O32  1  0.237  0.447  0.651  1.0
  O  O33  1  0.763  0.553  0.349  1.0
  O  O34  1  0.330  0.735  0.391  1.0
  O  O35  1  0.670  0.265  0.609  1.0
  O  O36  1  0.670  0.484  0.073  1.0
  O  O37  1  0.330  0.516  0.927  1.0
  O  O38  1  0.914  0.706  0.059  1.0
  O  O39  1  0.086  0.294  0.941  1.0
  O  O40  1  0.057  0.379  0.209  1.0
  O  O41  1  0.943  0.621  0.791  1.0
  O  O42  1  0.221  0.797  0.713  1.0
  O  O43  1  0.779  0.203  0.287  1.0
  O  O44  1  0.245  0.044  0.203  1.0
  O  O45  1  0.755  0.956  0.797  1.0
  O  O46  1  0.444  0.413  0.352  1.0
  O  O47  1  0.556  0.587  0.648  1.0
  O  O48  1  0.893  0.377  0.741  1.0
  O  O49  1  0.107  0.623  0.259  1.0
  O  O50  1  0.476  0.813  0.096  1.0
  O  O51  1  0.524  0.187  0.904  1.0
  O  O52  1  0.406  0.089  0.737  1.0
  O  O53  1  0.594  0.911  0.263  1.0
[/CIF]
.
The structure described by NH4Fe(HPO4)2 crystallizes in the triclinic P-1 space group. The structure consists of two ammonium molecules inside a Fe3P6NH10O24 framework. In the Fe3P6NH10O24 framework, there are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(9) atoms to form FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(1), one O(11), one O(4), one O(5), one O(6), and one O(8) atom to form FeO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. There are three inequivalent P sites. In the first P site, P(1) is bonded to one O(10), one O(2), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra and corners with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 15-56°. In the second P site, P(2) is bonded to one O(11), one O(12), one O(3), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra and corners with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 33-55°. In the third P site, P(3) is bonded to one O(1), one O(4), one O(7), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra and corners with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-49°. N(2) is bonded in a square co-planar geometry to two equivalent H(8) and two equivalent H(9) atoms. There are five inequivalent H sites. In the first H site, H(4) is bonded in a distorted single-bond geometry to one O(6) and one O(7) atom. In the second H site, H(6) is bonded in a distorted linear geometry to one O(1) and one O(12) atom. In the third H site, H(7) is bonded in a distorted linear geometry to one O(10) and one O(9) atom. In the fourth H site, H(8) is bonded in a linear geometry to one N(2) and one O(5) atom. In the fifth H site, H(9) is bonded in a single-bond geometry to one N(2) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Fe(2), one P(3), and one H(6) atom. In the second O site, O(2) is bonded in a linear geometry to one Fe(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Fe(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(3) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Fe(2), one P(1), and one H(8) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Fe(2), one P(1), and one H(4) atom. In the seventh O site, O(7) is bonded in a distorted water-like geometry to one P(3) and one H(4) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Fe(2) and one P(2) atom. In the ninth O site, O(9) is bonded in a distorted trigonal non-coplanar geometry to one Fe(1), one P(3), and one H(7) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one P(1) and one H(7) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the twelfth O site, O(12) is bonded in a water-like geometry to one P(2) and one H(6) atom. is represented by the CIF file [CIF]
data_FeP2H6NO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.216
_cell_length_b   8.831
_cell_length_c   9.637
_cell_angle_alpha   64.238
_cell_angle_beta   70.216
_cell_angle_gamma   70.024
_symmetry_Int_Tables_number   1
_cell_volume   506.534
_cell_formula_units_Z   3
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
  Fe  Fe0  1  0.500  0.500  0.500  1.0
  Fe  Fe1  1  0.297  0.280  0.051  1.0
  Fe  Fe2  1  0.703  0.720  0.949  1.0
  P  P3  1  0.956  0.561  0.219  1.0
  P  P4  1  0.044  0.439  0.781  1.0
  P  P5  1  0.410  0.874  0.236  1.0
  P  P6  1  0.590  0.126  0.764  1.0
  P  P7  1  0.590  0.344  0.221  1.0
  P  P8  1  0.410  0.656  0.779  1.0
  H  H9  1  0.802  0.785  0.431  1.0
  H  H10  1  0.198  0.215  0.569  1.0
  H  H11  1  0.154  0.203  0.413  1.0
  H  H12  1  0.846  0.797  0.587  1.0
  H  H13  1  0.965  0.206  0.573  1.0
  H  H14  1  0.035  0.794  0.427  1.0
  H  H15  1  0.106  0.739  0.742  1.0
  H  H16  1  0.894  0.261  0.258  1.0
  H  H17  1  0.162  0.029  0.588  1.0
  H  H18  1  0.838  0.971  0.412  1.0
  H  H19  1  0.425  0.961  0.771  1.0
  H  H20  1  0.575  0.039  0.229  1.0
  H  H21  1  0.765  0.461  0.708  1.0
  H  H22  1  0.235  0.539  0.292  1.0
  H  H23  1  0.042  0.127  0.975  1.0
  H  H24  1  0.958  0.873  0.025  1.0
  H  H25  1  0.887  0.071  0.940  1.0
  H  H26  1  0.113  0.929  0.060  1.0
  N  N27  1  0.120  0.163  0.535  1.0
  N  N28  1  0.880  0.837  0.465  1.0
  N  N29  1  0.000  0.000  0.000  1.0
  O  O30  1  0.516  0.759  0.811  1.0
  O  O31  1  0.484  0.241  0.189  1.0
  O  O32  1  0.237  0.447  0.651  1.0
  O  O33  1  0.763  0.553  0.349  1.0
  O  O34  1  0.330  0.735  0.391  1.0
  O  O35  1  0.670  0.265  0.609  1.0
  O  O36  1  0.670  0.484  0.073  1.0
  O  O37  1  0.330  0.516  0.927  1.0
  O  O38  1  0.914  0.706  0.059  1.0
  O  O39  1  0.086  0.294  0.941  1.0
  O  O40  1  0.057  0.379  0.209  1.0
  O  O41  1  0.943  0.621  0.791  1.0
  O  O42  1  0.221  0.797  0.713  1.0
  O  O43  1  0.779  0.203  0.287  1.0
  O  O44  1  0.245  0.044  0.203  1.0
  O  O45  1  0.755  0.956  0.797  1.0
  O  O46  1  0.444  0.413  0.352  1.0
  O  O47  1  0.556  0.587  0.648  1.0
  O  O48  1  0.893  0.377  0.741  1.0
  O  O49  1  0.107  0.623  0.259  1.0
  O  O50  1  0.476  0.813  0.096  1.0
  O  O51  1  0.524  0.187  0.904  1.0
  O  O52  1  0.406  0.089  0.737  1.0
  O  O53  1  0.594  0.911  0.263  1.0
[/CIF]
.