Gonnardite Lee Y, Hriljac J A, Vogt T American Mineralogist 90 (2005) 247-251 Variable-temperature structural studies of tetranatrolite from Mt. Saint-Hilaire: Synchrotron X-ray powder diffraction and Rietveld analysis Sample: T = 300 C, phase II _database_code_amcsd 0003726 13.1503 13.1503 6.2469 90 90 90 I-42d atom x y z occ Uiso SiT1 0 0 0 .537 .0155 AlT1 0 0 0 .463 .0155 SiT2 .0526 .1302 .6186 .537 .0155 AlT2 .0526 .1302 .6186 .463 .0155 O1 .3949 .25 .125 .0171 O2 .1378 .0433 .5635 .0171 O3 -.0019 .1102 .8594 .0171 Na -.0282 .25 .125 .731 .036 Ca .026 .25 .125 .237 .036 Wat5 .800 .25 .125 .201 .036