Nepheline Angel R J, Gatta G C, Boffa Ballaran T, Carpenter M A The Canadian Mineralogist 46 (2008) 1465-1476 The mechanism of coupling in the modulated structure of nepheline Locality: Snipe River, Tambani, Malawi Note: annealed Note: T = 15 K _database_code_amcsd 0006208 9.9801 9.9801 8.3707 90 90 120 P6_3 atom x y z occ Uiso K 0 0 .0037 .57 .022 Na1 0 0 .0037 .24 .022 Na2 .5554 .9976 .5086 .017 Al1 2/3 1/3 .7010 .48 .012 Si1 2/3 1/3 .7010 .52 .012 Al2 2/3 1/3 .3136 .48 .014 Si2 2/3 1/3 .3136 .52 .014 Al3 .9067 .6658 .8222 .48 .014 Si3 .9067 .6658 .8222 .52 .014 Al4 .9073 .6671 .1961 .48 .012 Si4 .9073 .6671 .1961 .52 .012 O1 .6602 .2797 .5053 1/3 .023 O2 .9732 .6814 .0034 .035 O3 .8287 .4781 .2515 .038 O4 .8365 .4889 .7610 .034 O5 .7746 .7152 .8251 .019 O6 .7762 .7315 .2007 .020