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 = 100 C
13.0666 13.0666 6.6632 90 90 90 I-42d
atom     x     y     z  occ  Uiso
SiT1     0     0     0 .537 .0083
AlT1     0     0     0 .463 .0083
SiT2 .0560 .1336 .6220 .537 .0083
AlT2 .0560 .1336 .6220 .463 .0083
O1   .3888   .25  .125      .0155
O2   .1351 .0590 .4857      .0155
O3   .0516 .0943 .8664      .0155
Na   .6923   .25  .125 .731 .0195
Ca   .6923   .25  .125 .237 .0195
Wat4 .1287   .25  .125       .023
Wat5  .895   .25  .125 .185  .023