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
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