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 I
12.9202 12.9202 6.6950 90 90 90 I-42d
atom    x    y    z  occ Uiso
SiT1    0    0    0 .537 .048
AlT1    0    0    0 .463 .048
SiT2 .051 .136 .625 .537 .048
AlT2 .051 .136 .625 .463 .048
O1   .392  .25 .125      .026
O2   .126 .069 .476      .026
O3   .045 .097 .862      .026
Na   .687  .25 .125 .731 .046
Ca   .687  .25 .125 .237 .046
Wat4 .134  .25 .125      .046