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 = 133 K
_database_code_amcsd 0013478
7.050 9.979 7.297 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  .0111  .0119  .0443      0 -.0033      0
Na2      0   .25   .75  .0143  .0247  .0123      0      0  .0072
Mg     .25     0     0  .0045  .0045  .0075      0  .0005      0
Al       0   .25   .25  .0049  .0047  .0074      0      0  .0013
F1       0     0 .8862  .0051  .0134  .0111      0      0      0
F3       0 .1644 .4713  .0120  .0105  .0094      0      0  .0002
F5   .1845 .1374 .1804  .0085  .0088  .0141  .0032  .0014 -.0038