Weberite
Knop O, Cameron T S, Jochem K
Journal of Solid State Chemistry 43 (1982) 213-221
What is the true space group of weberite?
Locality: Ivigtut, Greenland
Sample: Imma refinement, T = ambient
_database_code_amcsd 0013477
7.051 9.968 7.285 90 90 90 *Imma
0 .25 .25
atom     x     y     z U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3)
Na1    .25     0    .5  .0174  .0194  .0551      0 -.0046      0
Na2      0   .25   .75  .0222  .0333  .0143      0      0  .0095
Mg     .25     0     0  .0072  .0060  .0068      0  .0008      0
Al       0   .25   .25  .0076  .0067  .0070      0      0  .0019
F1       0     0 .8863  .0073  .0192  .0123      0      0      0
F3       0 .1648 .4709  .0177  .0152  .0092      0      0  .0014
F5   .1841 .1374 .1804  .0124  .0128  .0163  .0034  .0014 -.0059