data_global _chemical_name_mineral 'Fergusonite-(Y)' loop_ _publ_author_name 'Komkov A I' _journal_name_full 'Soviet Physics Crystallography' _journal_volume 4 _journal_year 1959 _journal_page_first 796 _journal_page_last 800 _publ_section_title ; The structure of natural fergusonite, and a polymorphic modification ; _database_code_amcsd 0015538 _chemical_compound_source 'Ural Mountains, Russia' _chemical_formula_sum '(Y.85 Yb.15) Nb O4' _cell_length_a 5.16 _cell_length_b 5.16 _cell_length_c 10.89 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 289.953 _exptl_crystal_density_diffrn 5.920 _symmetry_space_group_name_H-M 'I 41/a' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,1/2+z' '1/2+y,1/2-x,1/2-z' '+y,-x,-z' '-y,1/2+x,1/4+z' '1/2-y,+x,3/4+z' '1/2+x,y,3/4-z' '+x,1/2+y,1/4-z' '1/2-x,1/2-y,1/2+z' '-x,-y,+z' '-y,x,-z' '1/2-y,1/2+x,1/2-z' '1/2+y,-x,3/4+z' '+y,1/2-x,1/4+z' '-x,1/2-y,1/4-z' '1/2-x,-y,3/4-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy Y 0.00000 0.00000 0.50000 0.85000 Yb 0.00000 0.00000 0.50000 0.15000 Nb 0.00000 0.00000 0.00000 1.00000 O 0.18500 0.25000 0.09200 1.00000