The structure described by FeCu(PO4)2 crystallizes in the monoclinic P2_1/m space group. Fe(1) is bonded to one O(1), one O(5), two equivalent O(3), and two equivalent O(4) atoms to form distorted FeO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. Cu(1) is bonded in a rectangular see-saw-like geometry to one O(2), one O(6), and two equivalent O(4) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form PO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-51°. In the second P site, P(2) is bonded to one O(5), one O(6), and two equivalent O(4) atoms to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra and  an edgeedge with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 44°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Cu(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(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(1), one Cu(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Cu(1) and one P(2) atom. is represented by the CIF file [CIF]
data_FeCu(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.967
_cell_length_b   5.049
_cell_length_c   10.004
_cell_angle_alpha   86.361
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   300.783
_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  0.750  0.459  0.783  1.0
  Fe  Fe1  1  0.250  0.541  0.217  1.0
  Cu  Cu2  1  0.250  0.868  0.696  1.0
  Cu  Cu3  1  0.750  0.132  0.304  1.0
  P  P4  1  0.250  0.403  0.896  1.0
  P  P5  1  0.750  0.942  0.602  1.0
  P  P6  1  0.250  0.058  0.398  1.0
  P  P7  1  0.750  0.597  0.104  1.0
  O  O8  1  0.750  0.643  0.951  1.0
  O  O9  1  0.250  0.714  0.867  1.0
  O  O10  1  0.040  0.284  0.832  1.0
  O  O11  1  0.460  0.284  0.832  1.0
  O  O12  1  0.944  0.771  0.674  1.0
  O  O13  1  0.556  0.771  0.674  1.0
  O  O14  1  0.750  0.235  0.624  1.0
  O  O15  1  0.250  0.110  0.549  1.0
  O  O16  1  0.750  0.890  0.451  1.0
  O  O17  1  0.250  0.765  0.376  1.0
  O  O18  1  0.056  0.229  0.326  1.0
  O  O19  1  0.444  0.229  0.326  1.0
  O  O20  1  0.540  0.716  0.168  1.0
  O  O21  1  0.960  0.716  0.168  1.0
  O  O22  1  0.750  0.286  0.133  1.0
  O  O23  1  0.250  0.357  0.049  1.0
[/CIF]
.
The structure described by FeCu(PO4)2 crystallizes in the monoclinic P2_1/m space group. Fe(1) is bonded to one O(1), one O(5), two equivalent O(3), and two equivalent O(4) atoms to form distorted FeO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. Cu(1) is bonded in a rectangular see-saw-like geometry to one O(2), one O(6), and two equivalent O(4) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form PO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-51°. In the second P site, P(2) is bonded to one O(5), one O(6), and two equivalent O(4) atoms to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra and  an edgeedge with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 44°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Cu(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(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(1), one Cu(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Cu(1) and one P(2) atom. is represented by the CIF file [CIF]
data_FeCu(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.967
_cell_length_b   5.049
_cell_length_c   10.004
_cell_angle_alpha   86.361
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   300.783
_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  0.750  0.459  0.783  1.0
  Fe  Fe1  1  0.250  0.541  0.217  1.0
  Cu  Cu2  1  0.250  0.868  0.696  1.0
  Cu  Cu3  1  0.750  0.132  0.304  1.0
  P  P4  1  0.250  0.403  0.896  1.0
  P  P5  1  0.750  0.942  0.602  1.0
  P  P6  1  0.250  0.058  0.398  1.0
  P  P7  1  0.750  0.597  0.104  1.0
  O  O8  1  0.750  0.643  0.951  1.0
  O  O9  1  0.250  0.714  0.867  1.0
  O  O10  1  0.040  0.284  0.832  1.0
  O  O11  1  0.460  0.284  0.832  1.0
  O  O12  1  0.944  0.771  0.674  1.0
  O  O13  1  0.556  0.771  0.674  1.0
  O  O14  1  0.750  0.235  0.624  1.0
  O  O15  1  0.250  0.110  0.549  1.0
  O  O16  1  0.750  0.890  0.451  1.0
  O  O17  1  0.250  0.765  0.376  1.0
  O  O18  1  0.056  0.229  0.326  1.0
  O  O19  1  0.444  0.229  0.326  1.0
  O  O20  1  0.540  0.716  0.168  1.0
  O  O21  1  0.960  0.716  0.168  1.0
  O  O22  1  0.750  0.286  0.133  1.0
  O  O23  1  0.250  0.357  0.049  1.0
[/CIF]
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