The compound described by U2O(PO4)2 crystallizes in the orthorhombic Cmce space group. U(1) is bonded to one O(1), one O(2), one O(3), and four equivalent O(4) atoms to form distorted UO7 pentagonal bipyramids that share  a cornercorner with one U(1)O7 pentagonal bipyramid, corners with four equivalent P(1)O4 tetrahedra, edges with two equivalent U(1)O7 pentagonal bipyramids, and  an edgeedge with one P(1)O4 tetrahedra. P(1) is bonded to one O(1), one O(3), and two equivalent O(4) atoms to form PO4 tetrahedra that share corners with four equivalent U(1)O7 pentagonal bipyramids and  an edgeedge with one U(1)O7 pentagonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one U(1) and one P(1) atom. In the second O site, O(2) is bonded in a linear geometry to two equivalent U(1) atoms. In the third O site, O(3) is bonded in a linear geometry to one U(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent U(1) and one P(1) atom. is represented by the CIF file [CIF]
data_U2P2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.735
_cell_length_b   5.735
_cell_length_c   12.726
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   103.738
_symmetry_Int_Tables_number   1
_cell_volume   406.559
_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
  U  U0  1  0.209  0.791  0.430  1.0
  U  U1  1  0.291  0.709  0.930  1.0
  U  U2  1  0.791  0.209  0.570  1.0
  U  U3  1  0.709  0.291  0.070  1.0
  P  P4  1  0.109  0.891  0.143  1.0
  P  P5  1  0.391  0.609  0.643  1.0
  P  P6  1  0.891  0.109  0.857  1.0
  P  P7  1  0.609  0.391  0.357  1.0
  O  O8  1  0.942  0.058  0.123  1.0
  O  O9  1  0.558  0.442  0.623  1.0
  O  O10  1  0.058  0.942  0.877  1.0
  O  O11  1  0.442  0.558  0.377  1.0
  O  O12  1  0.500  0.500  0.000  1.0
  O  O13  1  0.000  0.000  0.500  1.0
  O  O14  1  0.640  0.360  0.240  1.0
  O  O15  1  0.860  0.140  0.740  1.0
  O  O16  1  0.853  0.486  0.414  1.0
  O  O17  1  0.647  0.014  0.914  1.0
  O  O18  1  0.486  0.853  0.586  1.0
  O  O19  1  0.014  0.647  0.086  1.0
  O  O20  1  0.147  0.514  0.586  1.0
  O  O21  1  0.353  0.986  0.086  1.0
  O  O22  1  0.514  0.147  0.414  1.0
  O  O23  1  0.986  0.353  0.914  1.0
  O  O24  1  0.140  0.860  0.260  1.0
  O  O25  1  0.360  0.640  0.760  1.0
[/CIF]
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The compound described by U2O(PO4)2 crystallizes in the orthorhombic Cmce space group. U(1) is bonded to one O(1), one O(2), one O(3), and four equivalent O(4) atoms to form distorted UO7 pentagonal bipyramids that share  a cornercorner with one U(1)O7 pentagonal bipyramid, corners with four equivalent P(1)O4 tetrahedra, edges with two equivalent U(1)O7 pentagonal bipyramids, and  an edgeedge with one P(1)O4 tetrahedra. P(1) is bonded to one O(1), one O(3), and two equivalent O(4) atoms to form PO4 tetrahedra that share corners with four equivalent U(1)O7 pentagonal bipyramids and  an edgeedge with one U(1)O7 pentagonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one U(1) and one P(1) atom. In the second O site, O(2) is bonded in a linear geometry to two equivalent U(1) atoms. In the third O site, O(3) is bonded in a linear geometry to one U(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent U(1) and one P(1) atom. is represented by the CIF file [CIF]
data_U2P2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.735
_cell_length_b   5.735
_cell_length_c   12.726
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   103.738
_symmetry_Int_Tables_number   1
_cell_volume   406.559
_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
  U  U0  1  0.209  0.791  0.430  1.0
  U  U1  1  0.291  0.709  0.930  1.0
  U  U2  1  0.791  0.209  0.570  1.0
  U  U3  1  0.709  0.291  0.070  1.0
  P  P4  1  0.109  0.891  0.143  1.0
  P  P5  1  0.391  0.609  0.643  1.0
  P  P6  1  0.891  0.109  0.857  1.0
  P  P7  1  0.609  0.391  0.357  1.0
  O  O8  1  0.942  0.058  0.123  1.0
  O  O9  1  0.558  0.442  0.623  1.0
  O  O10  1  0.058  0.942  0.877  1.0
  O  O11  1  0.442  0.558  0.377  1.0
  O  O12  1  0.500  0.500  0.000  1.0
  O  O13  1  0.000  0.000  0.500  1.0
  O  O14  1  0.640  0.360  0.240  1.0
  O  O15  1  0.860  0.140  0.740  1.0
  O  O16  1  0.853  0.486  0.414  1.0
  O  O17  1  0.647  0.014  0.914  1.0
  O  O18  1  0.486  0.853  0.586  1.0
  O  O19  1  0.014  0.647  0.086  1.0
  O  O20  1  0.147  0.514  0.586  1.0
  O  O21  1  0.353  0.986  0.086  1.0
  O  O22  1  0.514  0.147  0.414  1.0
  O  O23  1  0.986  0.353  0.914  1.0
  O  O24  1  0.140  0.860  0.260  1.0
  O  O25  1  0.360  0.640  0.760  1.0
[/CIF]
.