Nepheline Gatta G D, Angel R J American Mineralogist 92 (2007) 1446-1455 Elastic behavior and pressure-induced structural evolution of nepheline: Implications for the nature of the modulated superstructure Locality: intrusive aplite of Snipe River, Tambani, Nyasaland, Malawi Sample: P = 6.108 GPa _database_code_amcsd 0004426 9.6189 9.6189 8.1423 90 90 120 P6_3 atom x y z occ Uiso K 0 0 -.0073 .54 .0171 NaK 0 0 -.0073 .24 .0171 CaK 0 0 -.0073 .03 .0171 Na .55850 .00022 .5027 .0169 AlT1 2/3 1/3 .70282 .0085 SiT2 2/3 1/3 .29904 .0089 SiT3 .92093 .67173 .81891 .0081 AlT4 .92279 .67442 .18671 .0073 O1 2/3 1/3 .4957 .0355 O2 .00916 .70138 -.0036 .0138 O3 .8360 .47420 .2237 .0172 O4 .8486 .48610 .7632 .0175 O5 .77757 .71312 .8327 .0107 O6 .7868 .7399 .1798 .0135