The compound described by U3O7 crystallizes in the orthorhombic Immm space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a distorted body-centered cubic geometry to two equivalent O(3), four equivalent O(1), and four equivalent O(2) atoms. In the second U site, U(2) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(3), and six equivalent O(2) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent U(1) and two equivalent U(2) atoms to form OU4 tetrahedra that share corners with two equivalent O(3)U6 octahedra, corners with four equivalent O(1)U4 tetrahedra, corners with twelve equivalent O(2)U4 tetrahedra, edges with two equivalent O(1)U4 tetrahedra, edges with four equivalent O(2)U4 tetrahedra, and faces with two equivalent O(3)U6 octahedra. The corner-sharing octahedral tilt angles are 58°. In the second O site, O(2) is bonded to one U(1) and three equivalent U(2) atoms to form OU4 tetrahedra that share corners with five equivalent O(3)U6 octahedra, corners with six equivalent O(1)U4 tetrahedra, corners with ten equivalent O(2)U4 tetrahedra, edges with two equivalent O(1)U4 tetrahedra, edges with four equivalent O(2)U4 tetrahedra, and  a faceface with one O(3)U6 octahedra. The corner-sharing octahedral tilt angles range from 50-57°. In the third O site, O(3) is bonded to two equivalent U(1) and four equivalent U(2) atoms to form OU6 octahedra that share corners with two equivalent O(3)U6 octahedra, corners with four equivalent O(1)U4 tetrahedra, corners with twenty equivalent O(2)U4 tetrahedra, edges with two equivalent O(3)U6 octahedra, faces with four equivalent O(1)U4 tetrahedra, and faces with four equivalent O(2)U4 tetrahedra. The corner-sharing octahedra are not tilted. is represented by the CIF card [CIF]
data_U3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.569
_cell_length_b   6.569
_cell_length_c   6.569
_cell_angle_alpha   146.492
_cell_angle_beta   130.546
_cell_angle_gamma   61.062
_symmetry_Int_Tables_number   1
_cell_volume   117.773
_cell_formula_units_Z   1
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  0.000  0.000  0.000  1.0
  U  U1  1  0.655  0.655  0.000  1.0
  U  U2  1  0.345  0.345  0.000  1.0
  O  O3  1  0.783  0.500  0.283  1.0
  O  O4  1  0.411  0.177  0.234  1.0
  O  O5  1  0.057  0.823  0.234  1.0
  O  O6  1  0.217  0.500  0.717  1.0
  O  O7  1  0.943  0.177  0.766  1.0
  O  O8  1  0.589  0.823  0.766  1.0
  O  O9  1  0.500  0.000  0.500  1.0
[/CIF]
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The compound described by U3O7 crystallizes in the orthorhombic Immm space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a distorted body-centered cubic geometry to two equivalent O(3), four equivalent O(1), and four equivalent O(2) atoms. In the second U site, U(2) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(3), and six equivalent O(2) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent U(1) and two equivalent U(2) atoms to form OU4 tetrahedra that share corners with two equivalent O(3)U6 octahedra, corners with four equivalent O(1)U4 tetrahedra, corners with twelve equivalent O(2)U4 tetrahedra, edges with two equivalent O(1)U4 tetrahedra, edges with four equivalent O(2)U4 tetrahedra, and faces with two equivalent O(3)U6 octahedra. The corner-sharing octahedral tilt angles are 58°. In the second O site, O(2) is bonded to one U(1) and three equivalent U(2) atoms to form OU4 tetrahedra that share corners with five equivalent O(3)U6 octahedra, corners with six equivalent O(1)U4 tetrahedra, corners with ten equivalent O(2)U4 tetrahedra, edges with two equivalent O(1)U4 tetrahedra, edges with four equivalent O(2)U4 tetrahedra, and  a faceface with one O(3)U6 octahedra. The corner-sharing octahedral tilt angles range from 50-57°. In the third O site, O(3) is bonded to two equivalent U(1) and four equivalent U(2) atoms to form OU6 octahedra that share corners with two equivalent O(3)U6 octahedra, corners with four equivalent O(1)U4 tetrahedra, corners with twenty equivalent O(2)U4 tetrahedra, edges with two equivalent O(3)U6 octahedra, faces with four equivalent O(1)U4 tetrahedra, and faces with four equivalent O(2)U4 tetrahedra. The corner-sharing octahedra are not tilted. is represented by the CIF card [CIF]
data_U3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.569
_cell_length_b   6.569
_cell_length_c   6.569
_cell_angle_alpha   146.492
_cell_angle_beta   130.546
_cell_angle_gamma   61.062
_symmetry_Int_Tables_number   1
_cell_volume   117.773
_cell_formula_units_Z   1
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  0.000  0.000  0.000  1.0
  U  U1  1  0.655  0.655  0.000  1.0
  U  U2  1  0.345  0.345  0.000  1.0
  O  O3  1  0.783  0.500  0.283  1.0
  O  O4  1  0.411  0.177  0.234  1.0
  O  O5  1  0.057  0.823  0.234  1.0
  O  O6  1  0.217  0.500  0.717  1.0
  O  O7  1  0.943  0.177  0.766  1.0
  O  O8  1  0.589  0.823  0.766  1.0
  O  O9  1  0.500  0.000  0.500  1.0
[/CIF]
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