The material structure described by K2FeP2O7 crystallizes in the tetragonal P-42_1m space group. K(1) is bonded in a 8-coordinate geometry to one O(1), three equivalent O(2), and four equivalent O(3) atoms. Fe(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. P(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form corner-sharing PO4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent K(1) and two equivalent P(1) atoms. In the second O site, O(2) is bonded in a distorted single-bond geometry to three equivalent K(1) and one P(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent K(1), one Fe(1), and one P(1) atom. is represented by the CIF file [CIF]
data_K2FeP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.740
_cell_length_b   8.643
_cell_length_c   8.644
_cell_angle_alpha   90.000
_cell_angle_beta   89.996
_cell_angle_gamma   90.008
_symmetry_Int_Tables_number   1
_cell_volume   428.801
_cell_formula_units_Z   2
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  1.000  0.500  0.500  1.0
  Fe  Fe1  1  1.000  1.000  0.000  1.0
  K  K2  1  0.637  0.144  0.644  1.0
  K  K3  1  0.363  0.644  0.856  1.0
  K  K4  1  0.637  0.856  0.356  1.0
  K  K5  1  0.363  0.356  0.144  1.0
  O  O6  1  0.029  0.000  0.500  1.0
  O  O7  1  0.971  0.500  1.000  1.0
  O  O8  1  0.396  0.875  0.625  1.0
  O  O9  1  0.604  0.375  0.875  1.0
  O  O10  1  0.396  0.125  0.375  1.0
  O  O11  1  0.604  0.625  0.125  1.0
  O  O12  1  0.975  0.427  0.720  1.0
  O  O13  1  0.025  0.927  0.780  1.0
  O  O14  1  0.975  0.573  0.280  1.0
  O  O15  1  0.025  0.073  0.220  1.0
  O  O16  1  0.025  0.280  0.427  1.0
  O  O17  1  0.975  0.780  0.073  1.0
  O  O18  1  0.025  0.720  0.573  1.0
  O  O19  1  0.975  0.220  0.927  1.0
  P  P20  1  0.132  0.874  0.626  1.0
  P  P21  1  0.868  0.374  0.874  1.0
  P  P22  1  0.132  0.126  0.374  1.0
  P  P23  1  0.868  0.626  0.126  1.0
[/CIF]
.
The material structure described by K2FeP2O7 crystallizes in the tetragonal P-42_1m space group. K(1) is bonded in a 8-coordinate geometry to one O(1), three equivalent O(2), and four equivalent O(3) atoms. Fe(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. P(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form corner-sharing PO4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent K(1) and two equivalent P(1) atoms. In the second O site, O(2) is bonded in a distorted single-bond geometry to three equivalent K(1) and one P(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent K(1), one Fe(1), and one P(1) atom. is represented by the CIF file [CIF]
data_K2FeP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.740
_cell_length_b   8.643
_cell_length_c   8.644
_cell_angle_alpha   90.000
_cell_angle_beta   89.996
_cell_angle_gamma   90.008
_symmetry_Int_Tables_number   1
_cell_volume   428.801
_cell_formula_units_Z   2
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  1.000  0.500  0.500  1.0
  Fe  Fe1  1  1.000  1.000  0.000  1.0
  K  K2  1  0.637  0.144  0.644  1.0
  K  K3  1  0.363  0.644  0.856  1.0
  K  K4  1  0.637  0.856  0.356  1.0
  K  K5  1  0.363  0.356  0.144  1.0
  O  O6  1  0.029  0.000  0.500  1.0
  O  O7  1  0.971  0.500  1.000  1.0
  O  O8  1  0.396  0.875  0.625  1.0
  O  O9  1  0.604  0.375  0.875  1.0
  O  O10  1  0.396  0.125  0.375  1.0
  O  O11  1  0.604  0.625  0.125  1.0
  O  O12  1  0.975  0.427  0.720  1.0
  O  O13  1  0.025  0.927  0.780  1.0
  O  O14  1  0.975  0.573  0.280  1.0
  O  O15  1  0.025  0.073  0.220  1.0
  O  O16  1  0.025  0.280  0.427  1.0
  O  O17  1  0.975  0.780  0.073  1.0
  O  O18  1  0.025  0.720  0.573  1.0
  O  O19  1  0.975  0.220  0.927  1.0
  P  P20  1  0.132  0.874  0.626  1.0
  P  P21  1  0.868  0.374  0.874  1.0
  P  P22  1  0.132  0.126  0.374  1.0
  P  P23  1  0.868  0.626  0.126  1.0
[/CIF]
.