Alunite
Hendricks S B
American Mineralogist 22 (1937) 773-784
The crystal structures of alunite and the jarosites
_database_code_amcsd 0000016
6.96 6.96 17.35 90 90 120 R-3m
atom    x     y     z
K       0     0     0
S       0     0  .305
Al      0    .5    .5
O1      0     0  .393
O2   .215 -.215 -.058
OH3  .150 -.150  .126