data_global _chemical_name_mineral 'Nepheline' loop_ _publ_author_name 'Antao S M' 'Hassan I' _journal_name_full 'The Canadian Mineralogist' _journal_volume 48 _journal_year 2010 _journal_page_first 69 _journal_page_last 80 _publ_section_title ; Nepheline: structure of three samples from the Bancroft area, Ontario, obtained using synchrotron high-resolution powder x-ray diffraction Sample: 3 ; _database_code_amcsd 0006320 _chemical_compound_source 'Davis Hill, Bancroft area, Ontario, Canada' _chemical_formula_sum 'K.778 Na3 Al4 Si2 O18' _cell_length_a 9.99567 _cell_length_b 9.99567 _cell_length_c 8.37873 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 724.991 _exptl_crystal_density_diffrn 2.526 _symmetry_space_group_name_H-M 'P 63' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x-y,x,1/2+z' '-y,x-y,z' '-x,-y,1/2+z' '-x+y,-x,z' 'y,-x+y,1/2+z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy _atom_site_U_iso_or_equiv K1 0.00000 0.00000 0.99920 0.77800 0.02090 Na1 0.44381 0.99730 0.99870 1.00000 0.02590 Al1 0.66667 0.33333 0.80350 1.00000 0.00960 Al2 0.33690 0.09480 0.31050 1.00000 0.00880 Si1 0.66667 0.33333 0.19340 1.00000 0.00960 Si2 0.33050 0.09290 0.68420 0.33333 0.00880 O1 0.71250 0.34520 0.00630 1.00000 0.02200 O2 0.31660 0.02800 0.49960 1.00000 0.02340 O3 0.51380 0.16720 0.71980 1.00000 0.02340 O4 0.51950 0.17340 0.23470 1.00000 0.02340 O5 0.26630 0.22360 0.30080 1.00000 0.02340 O6 0.28340 0.22520 0.68280 1.00000 0.02340