The crystal structure described by Na3UO4 is Caswellsilverite-like structured and crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NaO6 octahedra that share corners with six equivalent Na(1)O6 octahedra, edges with four equivalent Na(1)O6 octahedra, edges with four equivalent Na(2)O6 octahedra, and edges with four equivalent U(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-14°. In the second Na site, Na(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form NaO6 octahedra that share corners with six equivalent U(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent U(1)O6 octahedra, and edges with eight equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. U(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form UO6 octahedra that share corners with six equivalent Na(2)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent U(1)O6 octahedra, and edges with eight equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Na(2), four equivalent Na(1), and one U(1) atom to form distorted ONa5U octahedra that share corners with six equivalent O(1)Na5U octahedra, edges with four equivalent O(1)Na5U octahedra, and edges with eight equivalent O(2)Na4U2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent U(1) atoms to form ONa4U2 octahedra that share corners with six equivalent O(2)Na4U2 octahedra, edges with four equivalent O(2)Na4U2 octahedra, and edges with eight equivalent O(1)Na5U octahedra. The corner-sharing octahedra are not tilted. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na3UO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.474
_cell_length_b   5.713
_cell_length_c   5.713
_cell_angle_alpha   107.993
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   107.838
_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
  Na  Na0  1  0.500  0.500  0.000  1.0
  Na  Na1  1  0.500  0.000  0.500  1.0
  Na  Na2  1  0.000  0.500  0.500  1.0
  O  O3  1  0.000  0.218  0.782  1.0
  O  O4  1  0.500  0.784  0.784  1.0
  O  O5  1  0.500  0.216  0.216  1.0
  O  O6  1  1.000  0.782  0.218  1.0
  U  U7  1  0.000  0.000  0.000  1.0
[/CIF]
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The crystal structure described by Na3UO4 is Caswellsilverite-like structured and crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NaO6 octahedra that share corners with six equivalent Na(1)O6 octahedra, edges with four equivalent Na(1)O6 octahedra, edges with four equivalent Na(2)O6 octahedra, and edges with four equivalent U(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-14°. In the second Na site, Na(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form NaO6 octahedra that share corners with six equivalent U(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent U(1)O6 octahedra, and edges with eight equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. U(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form UO6 octahedra that share corners with six equivalent Na(2)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent U(1)O6 octahedra, and edges with eight equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Na(2), four equivalent Na(1), and one U(1) atom to form distorted ONa5U octahedra that share corners with six equivalent O(1)Na5U octahedra, edges with four equivalent O(1)Na5U octahedra, and edges with eight equivalent O(2)Na4U2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent U(1) atoms to form ONa4U2 octahedra that share corners with six equivalent O(2)Na4U2 octahedra, edges with four equivalent O(2)Na4U2 octahedra, and edges with eight equivalent O(1)Na5U octahedra. The corner-sharing octahedra are not tilted. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na3UO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.474
_cell_length_b   5.713
_cell_length_c   5.713
_cell_angle_alpha   107.993
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   107.838
_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
  Na  Na0  1  0.500  0.500  0.000  1.0
  Na  Na1  1  0.500  0.000  0.500  1.0
  Na  Na2  1  0.000  0.500  0.500  1.0
  O  O3  1  0.000  0.218  0.782  1.0
  O  O4  1  0.500  0.784  0.784  1.0
  O  O5  1  0.500  0.216  0.216  1.0
  O  O6  1  1.000  0.782  0.218  1.0
  U  U7  1  0.000  0.000  0.000  1.0
[/CIF]
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