The compound described by K2U2O7 crystallizes in the triclinic P-1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(5), two equivalent O(1), and two equivalent O(7) atoms. In the second K site, K(2) is bonded in a 6-coordinate geometry to one O(1), one O(4), one O(7), two equivalent O(3), and two equivalent O(5) atoms. There are three inequivalent U sites. In the first U site, U(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(6), two equivalent O(2), and two equivalent O(4) atoms. In the second U site, U(2) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms to form corner-sharing UO6 octahedra. The corner-sharing octahedral tilt angles are 49°. In the third U site, U(3) is bonded to two equivalent O(2), two equivalent O(6), and two equivalent O(7) atoms to form corner-sharing UO6 octahedra. The corner-sharing octahedral tilt angles are 49°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one K(2), two equivalent K(1), and one U(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one U(3), and two equivalent U(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to one K(1), two equivalent K(2), and one U(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one K(2), one U(2), and two equivalent U(1) atoms. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one K(1), two equivalent K(2), and one U(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one U(1), one U(2), and one U(3) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one K(2), two equivalent K(1), and one U(3) atom. is represented by the CIF file [CIF]
data_K2U2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.913
_cell_length_b   7.054
_cell_length_c   7.952
_cell_angle_alpha   106.316
_cell_angle_beta   89.822
_cell_angle_gamma   99.519
_symmetry_Int_Tables_number   1
_cell_volume   366.651
_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
  K  K0  1  0.241  0.484  0.625  1.0
  K  K1  1  0.263  0.489  0.119  1.0
  K  K2  1  0.759  0.516  0.375  1.0
  K  K3  1  0.737  0.511  0.881  1.0
  U  U4  1  0.032  0.993  0.246  1.0
  U  U5  1  0.968  0.007  0.754  1.0
  U  U6  1  0.500  0.000  0.000  1.0
  U  U7  1  0.500  0.000  0.500  1.0
  O  O8  1  0.069  0.271  0.315  1.0
  O  O9  1  0.189  0.020  0.555  1.0
  O  O10  1  0.012  0.285  0.823  1.0
  O  O11  1  0.190  0.021  0.959  1.0
  O  O12  1  0.559  0.282  0.084  1.0
  O  O13  1  0.441  0.718  0.916  1.0
  O  O14  1  0.367  0.979  0.245  1.0
  O  O15  1  0.556  0.281  0.556  1.0
  O  O16  1  0.444  0.719  0.444  1.0
  O  O17  1  0.811  0.980  0.445  1.0
  O  O18  1  0.633  0.021  0.755  1.0
  O  O19  1  0.931  0.729  0.685  1.0
  O  O20  1  0.810  0.979  0.041  1.0
  O  O21  1  0.988  0.715  0.177  1.0
[/CIF]
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The compound described by K2U2O7 crystallizes in the triclinic P-1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(5), two equivalent O(1), and two equivalent O(7) atoms. In the second K site, K(2) is bonded in a 6-coordinate geometry to one O(1), one O(4), one O(7), two equivalent O(3), and two equivalent O(5) atoms. There are three inequivalent U sites. In the first U site, U(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(6), two equivalent O(2), and two equivalent O(4) atoms. In the second U site, U(2) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms to form corner-sharing UO6 octahedra. The corner-sharing octahedral tilt angles are 49°. In the third U site, U(3) is bonded to two equivalent O(2), two equivalent O(6), and two equivalent O(7) atoms to form corner-sharing UO6 octahedra. The corner-sharing octahedral tilt angles are 49°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one K(2), two equivalent K(1), and one U(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one U(3), and two equivalent U(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to one K(1), two equivalent K(2), and one U(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one K(2), one U(2), and two equivalent U(1) atoms. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one K(1), two equivalent K(2), and one U(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one U(1), one U(2), and one U(3) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one K(2), two equivalent K(1), and one U(3) atom. is represented by the CIF file [CIF]
data_K2U2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.913
_cell_length_b   7.054
_cell_length_c   7.952
_cell_angle_alpha   106.316
_cell_angle_beta   89.822
_cell_angle_gamma   99.519
_symmetry_Int_Tables_number   1
_cell_volume   366.651
_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
  K  K0  1  0.241  0.484  0.625  1.0
  K  K1  1  0.263  0.489  0.119  1.0
  K  K2  1  0.759  0.516  0.375  1.0
  K  K3  1  0.737  0.511  0.881  1.0
  U  U4  1  0.032  0.993  0.246  1.0
  U  U5  1  0.968  0.007  0.754  1.0
  U  U6  1  0.500  0.000  0.000  1.0
  U  U7  1  0.500  0.000  0.500  1.0
  O  O8  1  0.069  0.271  0.315  1.0
  O  O9  1  0.189  0.020  0.555  1.0
  O  O10  1  0.012  0.285  0.823  1.0
  O  O11  1  0.190  0.021  0.959  1.0
  O  O12  1  0.559  0.282  0.084  1.0
  O  O13  1  0.441  0.718  0.916  1.0
  O  O14  1  0.367  0.979  0.245  1.0
  O  O15  1  0.556  0.281  0.556  1.0
  O  O16  1  0.444  0.719  0.444  1.0
  O  O17  1  0.811  0.980  0.445  1.0
  O  O18  1  0.633  0.021  0.755  1.0
  O  O19  1  0.931  0.729  0.685  1.0
  O  O20  1  0.810  0.979  0.041  1.0
  O  O21  1  0.988  0.715  0.177  1.0
[/CIF]
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