Tugtupite
Hassan I, Grundy H D
The Canadian Mineralogist 29 (1991) 385-390
The crystal structure and thermal expansion of tugtupite,
Na8[Al2Be2Si8O24]Cl2
_database_code_amcsd 0005268
8.640 8.640 8.873 90 90 90 I-4
atom     x     y     z U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3)
Al       0   1/2   3/4  .0078  .0078  .0074      0      0      0
Be       0   1/2   1/4  .0086  .0086  .0123      0      0      0
Si   .0127 .2533 .4958  .0071  .0063  .0086 -.0002 -.0002 -.0003
O1   .1504 .1343 .4417  .0126  .0116  .0128  .0046  .0010  .0001
O2   .3472 .0385 .6488  .0107  .0119  .0132 -.0003 -.0035 -.0004
O3   .4256 .1486 .1377  .0112  .0114  .0135 -.0001  .0005  .0038
Na   .1563 .1972 .1818  .0206  .0160  .0199  .0007  .0024  .0012
Cl       0     0     0  .0228  .0228  .0244      0      0      0