data_1001183 _chemical_name_systematic ; Sodium uranium(VI) niobium oxide (.8/.5/2/6.8) ; _chemical_formula_structural 'Na.82 U.45 Nb2 O6.76' _chemical_formula_sum 'Na.82 Nb2 O6.76 U.45' _publ_section_title ; Mise en evidence d'une transformation ordre-desordre dans un cristal de type pyrochlore. ; loop_ _publ_author_name 'Chevalier, R' 'Gasperin, M' _journal_name_full 'Acta Crystallographica B (24,1968-38,1982)' _journal_coden_ASTM ACBCAR _journal_volume 28 _journal_year 1972 _journal_page_first 985 _journal_page_last 986 _cell_length_a 10.4 _cell_length_b 10.4 _cell_length_c 10.4 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 1124.9 _cell_formula_units_Z 8 _symmetry_space_group_name_H-M 'F d -3 m S' _symmetry_Int_Tables_number 227 _symmetry_cell_setting cubic loop_ _symmetry_equiv_pos_as_xyz 'x,y,z' 'y,z,x' 'z,x,y' 'x,z,y' 'y,x,z' 'z,y,x' 'x,-y,-z' 'y,-z,-x' 'z,-x,-y' 'x,-z,-y' 'y,-x,-z' 'z,-y,-x' '-x,y,-z' '-y,z,-x' '-z,x,-y' '-x,z,-y' '-y,x,-z' '-z,y,-x' '-x,-y,z' '-y,-z,x' '-z,-x,y' '-x,-z,y' '-y,-x,z' '-z,-y,x' '1/4-x,1/4-y,1/4-z' '1/4-y,1/4-z,1/4-x' '1/4-z,1/4-x,1/4-y' '1/4-x,1/4-z,1/4-y' '1/4-y,1/4-x,1/4-z' '1/4-z,1/4-y,1/4-x' '1/4-x,1/4+y,1/4+z' '1/4-y,1/4+z,1/4+x' '1/4-z,1/4+x,1/4+y' '1/4-x,1/4+z,1/4+y' '1/4-y,1/4+x,1/4+z' '1/4-z,1/4+y,1/4+x' '1/4+x,1/4-y,1/4+z' '1/4+y,1/4-z,1/4+x' '1/4+z,1/4-x,1/4+y' '1/4+x,1/4-z,1/4+y' '1/4+y,1/4-x,1/4+z' '1/4+z,1/4-y,1/4+x' '1/4+x,1/4+y,1/4-z' '1/4+y,1/4+z,1/4-x' '1/4+z,1/4+x,1/4-y' '1/4+x,1/4+z,1/4-y' '1/4+y,1/4+x,1/4-z' '1/4+z,1/4+y,1/4-x' 'x,1/2+y,1/2+z' '1/2+x,y,1/2+z' '1/2+x,1/2+y,z' 'y,1/2+z,1/2+x' '1/2+y,z,1/2+x' '1/2+y,1/2+z,x' 'z,1/2+x,1/2+y' '1/2+z,x,1/2+y' '1/2+z,1/2+x,y' 'x,1/2+z,1/2+y' '1/2+x,z,1/2+y' '1/2+x,1/2+z,y' 'y,1/2+x,1/2+z' '1/2+y,x,1/2+z' '1/2+y,1/2+x,z' 'z,1/2+y,1/2+x' '1/2+z,y,1/2+x' '1/2+z,1/2+y,x' 'x,1/2-y,1/2-z' '1/2+x,-y,1/2-z' '1/2+x,1/2-y,-z' 'y,1/2-z,1/2-x' '1/2+y,-z,1/2-x' '1/2+y,1/2-z,-x' 'z,1/2-x,1/2-y' '1/2+z,-x,1/2-y' '1/2+z,1/2-x,-y' 'x,1/2-z,1/2-y' '1/2+x,-z,1/2-y' '1/2+x,1/2-z,-y' 'y,1/2-x,1/2-z' '1/2+y,-x,1/2-z' '1/2+y,1/2-x,-z' 'z,1/2-y,1/2-x' '1/2+z,-y,1/2-x' '1/2+z,1/2-y,-x' '-x,1/2+y,1/2-z' '1/2-x,y,1/2-z' '1/2-x,1/2+y,-z' '-y,1/2+z,1/2-x' '1/2-y,z,1/2-x' '1/2-y,1/2+z,-x' '-z,1/2+x,1/2-y' '1/2-z,x,1/2-y' '1/2-z,1/2+x,-y' '-x,1/2+z,1/2-y' '1/2-x,z,1/2-y' '1/2-x,1/2+z,-y' '-y,1/2+x,1/2-z' '1/2-y,x,1/2-z' '1/2-y,1/2+x,-z' '-z,1/2+y,1/2-x' '1/2-z,y,1/2-x' '1/2-z,1/2+y,-x' '-x,1/2-y,1/2+z' '1/2-x,-y,1/2+z' '1/2-x,1/2-y,z' '-y,1/2-z,1/2+x' '1/2-y,-z,1/2+x' '1/2-y,1/2-z,x' '-z,1/2-x,1/2+y' '1/2-z,-x,1/2+y' '1/2-z,1/2-x,y' '-x,1/2-z,1/2+y' '1/2-x,-z,1/2+y' '1/2-x,1/2-z,y' '-y,1/2-x,1/2+z' '1/2-y,-x,1/2+z' '1/2-y,1/2-x,z' '-z,1/2-y,1/2+x' '1/2-z,-y,1/2+x' '1/2-z,1/2-y,x' '1/4-x,3/4-y,3/4-z' '3/4-x,1/4-y,3/4-z' '3/4-x,3/4-y,1/4-z' '1/4-y,3/4-z,3/4-x' '3/4-y,1/4-z,3/4-x' '3/4-y,3/4-z,1/4-x' '1/4-z,3/4-x,3/4-y' '3/4-z,1/4-x,3/4-y' '3/4-z,3/4-x,1/4-y' '1/4-x,3/4-z,3/4-y' '3/4-x,1/4-z,3/4-y' '3/4-x,3/4-z,1/4-y' '1/4-y,3/4-x,3/4-z' '3/4-y,1/4-x,3/4-z' '3/4-y,3/4-x,1/4-z' '1/4-z,3/4-y,3/4-x' '3/4-z,1/4-y,3/4-x' '3/4-z,3/4-y,1/4-x' '1/4-x,3/4+y,3/4+z' '3/4-x,1/4+y,3/4+z' '3/4-x,3/4+y,1/4+z' '1/4-y,3/4+z,3/4+x' '3/4-y,1/4+z,3/4+x' '3/4-y,3/4+z,1/4+x' '1/4-z,3/4+x,3/4+y' '3/4-z,1/4+x,3/4+y' '3/4-z,3/4+x,1/4+y' '1/4-x,3/4+z,3/4+y' '3/4-x,1/4+z,3/4+y' '3/4-x,3/4+z,1/4+y' '1/4-y,3/4+x,3/4+z' '3/4-y,1/4+x,3/4+z' '3/4-y,3/4+x,1/4+z' '1/4-z,3/4+y,3/4+x' '3/4-z,1/4+y,3/4+x' '3/4-z,3/4+y,1/4+x' '1/4+x,3/4-y,3/4+z' '3/4+x,1/4-y,3/4+z' '3/4+x,3/4-y,1/4+z' '1/4+y,3/4-z,3/4+x' '3/4+y,1/4-z,3/4+x' '3/4+y,3/4-z,1/4+x' '1/4+z,3/4-x,3/4+y' '3/4+z,1/4-x,3/4+y' '3/4+z,3/4-x,1/4+y' '1/4+x,3/4-z,3/4+y' '3/4+x,1/4-z,3/4+y' '3/4+x,3/4-z,1/4+y' '1/4+y,3/4-x,3/4+z' '3/4+y,1/4-x,3/4+z' '3/4+y,3/4-x,1/4+z' '1/4+z,3/4-y,3/4+x' '3/4+z,1/4-y,3/4+x' '3/4+z,3/4-y,1/4+x' '1/4+x,3/4+y,3/4-z' '3/4+x,1/4+y,3/4-z' '3/4+x,3/4+y,1/4-z' '1/4+y,3/4+z,3/4-x' '3/4+y,1/4+z,3/4-x' '3/4+y,3/4+z,1/4-x' '1/4+z,3/4+x,3/4-y' '3/4+z,1/4+x,3/4-y' '3/4+z,3/4+x,1/4-y' '1/4+x,3/4+z,3/4-y' '3/4+x,1/4+z,3/4-y' '3/4+x,3/4+z,1/4-y' '1/4+y,3/4+x,3/4-z' '3/4+y,1/4+x,3/4-z' '3/4+y,3/4+x,1/4-z' '1/4+z,3/4+y,3/4-x' '3/4+z,1/4+y,3/4-x' '3/4+z,3/4+y,1/4-x' loop_ _atom_type_symbol _atom_type_oxidation_number U6+ 6.000 Na1+ 1.000 Nb5+ 5.000 O2- -2.000 loop_ _atom_site_label _atom_site_type_symbol _atom_site_symmetry_multiplicity _atom_site_Wyckoff_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy _atom_site_attached_hydrogens _atom_site_calc_flag U1 U6+ 16 d 0.625 0.625 0.625 0.225 0 d Na1 Na1+ 16 d 0.625 0.625 0.625 0.41 0 d Nb1 Nb5+ 16 c 0.125 0.125 0.125 1. 0 d O1 O2- 8 b 0.5 0.5 0.5 0.76 0 d O2 O2- 48 f 0.187 0. 0. 1. 0 d _refine_ls_R_factor_all 0.1