Tugtupite
Antao S M, Hassan I, Parise J B
American Mineralogist 89 (2004) 492-497
Tugtupite: High-temperature structures obtained from in situ synchrotron
diffraction and Rietveld refinements
T = 821 C
_database_code_amcsd 0003462
8.69872 8.69872 8.9107 90 90 90 I-4
atom     x     y     z  Uiso
Al       0    .5   .75 .0200
Be       0    .5   .25  .013
Si   .0118 .2541 .4949 .0200
O1   .1496 .1385 .4497 .0256
O2   .3435 .0321 .6526 .0256
O3   .4344 .1459 .1400 .0256
Na   .1626 .1983 .1832 .0634
Cl       0     0     0 .0834