The material described by KFe2(PO4)2 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(4), one O(7), one O(8), two equivalent O(5), and two equivalent O(6) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(6), and two equivalent O(4) atoms to form distorted FeO5 trigonal bipyramids that share corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one P(1)O4 tetrahedra, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 53-66°. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(5), one O(7), and one O(8) atom to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and corners with two equivalent Fe(1)O5 trigonal bipyramids. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Fe(2)O6 octahedra,  a cornercorner with one Fe(1)O5 trigonal bipyramid, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 33-44°. In the second P site, P(2) is bonded to one O(2), one O(4), one O(5), and one O(8) atom to form PO4 tetrahedra that share corners with three equivalent Fe(2)O6 octahedra and corners with two equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 37-41°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one Fe(1), one Fe(2), and one P(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one K(1), one Fe(2), and one P(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one K(1), two equivalent Fe(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to two equivalent K(1), one Fe(2), and one P(2) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to two equivalent K(1), one Fe(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one K(1), one Fe(2), and one P(1) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one K(1), one Fe(2), and one P(2) atom. is represented by the CIF card [CIF]
data_KFe2(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.229
_cell_length_b   8.001
_cell_length_c   9.277
_cell_angle_alpha   64.459
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   685.026
_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  0.359  0.353  0.573  1.0
  K  K1  1  0.859  0.647  0.927  1.0
  K  K2  1  0.641  0.647  0.427  1.0
  K  K3  1  0.141  0.353  0.073  1.0
  Fe  Fe4  1  0.618  0.936  0.946  1.0
  Fe  Fe5  1  0.122  0.729  0.256  1.0
  Fe  Fe6  1  0.622  0.271  0.244  1.0
  Fe  Fe7  1  0.118  0.064  0.554  1.0
  Fe  Fe8  1  0.882  0.936  0.446  1.0
  Fe  Fe9  1  0.378  0.729  0.756  1.0
  Fe  Fe10  1  0.382  0.064  0.054  1.0
  Fe  Fe11  1  0.878  0.271  0.744  1.0
  P  P12  1  0.160  0.007  0.864  1.0
  P  P13  1  0.840  0.993  0.136  1.0
  P  P14  1  0.904  0.386  0.352  1.0
  P  P15  1  0.096  0.614  0.648  1.0
  P  P16  1  0.404  0.614  0.148  1.0
  P  P17  1  0.660  0.993  0.636  1.0
  P  P18  1  0.340  0.007  0.364  1.0
  P  P19  1  0.596  0.386  0.852  1.0
  O  O20  1  0.749  0.058  0.239  1.0
  O  O21  1  0.871  0.406  0.506  1.0
  O  O22  1  0.956  0.894  0.255  1.0
  O  O23  1  0.965  0.190  0.396  1.0
  O  O24  1  0.249  0.942  0.261  1.0
  O  O25  1  0.495  0.532  0.746  1.0
  O  O26  1  0.044  0.106  0.745  1.0
  O  O27  1  0.235  0.153  0.901  1.0
  O  O28  1  0.110  0.845  0.015  1.0
  O  O29  1  0.219  0.590  0.750  1.0
  O  O30  1  0.995  0.468  0.754  1.0
  O  O31  1  0.390  0.845  0.515  1.0
  O  O32  1  0.890  0.155  0.985  1.0
  O  O33  1  0.610  0.155  0.485  1.0
  O  O34  1  0.251  0.942  0.761  1.0
  O  O35  1  0.035  0.810  0.604  1.0
  O  O36  1  0.629  0.406  0.006  1.0
  O  O37  1  0.751  0.058  0.739  1.0
  O  O38  1  0.735  0.847  0.599  1.0
  O  O39  1  0.281  0.590  0.250  1.0
  O  O40  1  0.505  0.468  0.254  1.0
  O  O41  1  0.535  0.190  0.896  1.0
  O  O42  1  0.265  0.153  0.401  1.0
  O  O43  1  0.005  0.532  0.246  1.0
  O  O44  1  0.719  0.410  0.750  1.0
  O  O45  1  0.781  0.410  0.250  1.0
  O  O46  1  0.544  0.894  0.755  1.0
  O  O47  1  0.765  0.847  0.099  1.0
  O  O48  1  0.129  0.594  0.494  1.0
  O  O49  1  0.465  0.810  0.104  1.0
  O  O50  1  0.371  0.594  0.994  1.0
  O  O51  1  0.456  0.106  0.245  1.0
[/CIF]
.
The material described by KFe2(PO4)2 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(4), one O(7), one O(8), two equivalent O(5), and two equivalent O(6) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(6), and two equivalent O(4) atoms to form distorted FeO5 trigonal bipyramids that share corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one P(1)O4 tetrahedra, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 53-66°. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(5), one O(7), and one O(8) atom to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and corners with two equivalent Fe(1)O5 trigonal bipyramids. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Fe(2)O6 octahedra,  a cornercorner with one Fe(1)O5 trigonal bipyramid, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 33-44°. In the second P site, P(2) is bonded to one O(2), one O(4), one O(5), and one O(8) atom to form PO4 tetrahedra that share corners with three equivalent Fe(2)O6 octahedra and corners with two equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 37-41°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one Fe(1), one Fe(2), and one P(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one K(1), one Fe(2), and one P(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one K(1), two equivalent Fe(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to two equivalent K(1), one Fe(2), and one P(2) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to two equivalent K(1), one Fe(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one K(1), one Fe(2), and one P(1) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one K(1), one Fe(2), and one P(2) atom. is represented by the CIF card [CIF]
data_KFe2(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.229
_cell_length_b   8.001
_cell_length_c   9.277
_cell_angle_alpha   64.459
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   685.026
_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  0.359  0.353  0.573  1.0
  K  K1  1  0.859  0.647  0.927  1.0
  K  K2  1  0.641  0.647  0.427  1.0
  K  K3  1  0.141  0.353  0.073  1.0
  Fe  Fe4  1  0.618  0.936  0.946  1.0
  Fe  Fe5  1  0.122  0.729  0.256  1.0
  Fe  Fe6  1  0.622  0.271  0.244  1.0
  Fe  Fe7  1  0.118  0.064  0.554  1.0
  Fe  Fe8  1  0.882  0.936  0.446  1.0
  Fe  Fe9  1  0.378  0.729  0.756  1.0
  Fe  Fe10  1  0.382  0.064  0.054  1.0
  Fe  Fe11  1  0.878  0.271  0.744  1.0
  P  P12  1  0.160  0.007  0.864  1.0
  P  P13  1  0.840  0.993  0.136  1.0
  P  P14  1  0.904  0.386  0.352  1.0
  P  P15  1  0.096  0.614  0.648  1.0
  P  P16  1  0.404  0.614  0.148  1.0
  P  P17  1  0.660  0.993  0.636  1.0
  P  P18  1  0.340  0.007  0.364  1.0
  P  P19  1  0.596  0.386  0.852  1.0
  O  O20  1  0.749  0.058  0.239  1.0
  O  O21  1  0.871  0.406  0.506  1.0
  O  O22  1  0.956  0.894  0.255  1.0
  O  O23  1  0.965  0.190  0.396  1.0
  O  O24  1  0.249  0.942  0.261  1.0
  O  O25  1  0.495  0.532  0.746  1.0
  O  O26  1  0.044  0.106  0.745  1.0
  O  O27  1  0.235  0.153  0.901  1.0
  O  O28  1  0.110  0.845  0.015  1.0
  O  O29  1  0.219  0.590  0.750  1.0
  O  O30  1  0.995  0.468  0.754  1.0
  O  O31  1  0.390  0.845  0.515  1.0
  O  O32  1  0.890  0.155  0.985  1.0
  O  O33  1  0.610  0.155  0.485  1.0
  O  O34  1  0.251  0.942  0.761  1.0
  O  O35  1  0.035  0.810  0.604  1.0
  O  O36  1  0.629  0.406  0.006  1.0
  O  O37  1  0.751  0.058  0.739  1.0
  O  O38  1  0.735  0.847  0.599  1.0
  O  O39  1  0.281  0.590  0.250  1.0
  O  O40  1  0.505  0.468  0.254  1.0
  O  O41  1  0.535  0.190  0.896  1.0
  O  O42  1  0.265  0.153  0.401  1.0
  O  O43  1  0.005  0.532  0.246  1.0
  O  O44  1  0.719  0.410  0.750  1.0
  O  O45  1  0.781  0.410  0.250  1.0
  O  O46  1  0.544  0.894  0.755  1.0
  O  O47  1  0.765  0.847  0.099  1.0
  O  O48  1  0.129  0.594  0.494  1.0
  O  O49  1  0.465  0.810  0.104  1.0
  O  O50  1  0.371  0.594  0.994  1.0
  O  O51  1  0.456  0.106  0.245  1.0
[/CIF]
.