Clarkeite
Finch R J, Ewing R C
American Mineralogist 82 (1997) 607-619
Clarkeite: New chemical and structural data
_database_code_amcsd 0001902
3.954 3.954 17.660 90 90 120 R-3m
atom x y     z Biso
U    0 0     0  .29
Na   0 0    .5  .54
O1   0 0 .1069  .42
O2   0 0 .3488  .42