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 = 65 C _database_code_amcsd 0003452 8.62591 8.62591 8.8562 90 90 90 I-4 atom x y z Uiso Al 0 .5 .75 .0126 Be 0 .5 .25 .006 Si .0133 .2541 .4947 .0126 O1 .1502 .1363 .4427 .0111 O2 .3436 .0354 .6505 .0111 O3 .4250 .1434 .1391 .0111 Na .1573 .1967 .1824 .0276 Cl 0 0 0 .0304