Chalcocite
Tomeoka K, Ohmasa M
American Mineralogist 67 (1982) 360-372
The modulated structure of cubic Cu9BiS6
the alpha phase
_database_code_amcsd 0000864
5.563 5.563 5.563 90 90 90 Fm3m
atom     x     y     z  occ Biso
Bi      .5    .5    .5 .138 4.86
Cu1  .2787 .2787 .2787 .109 1.59
Cu2  .3333 .3333 .3333 .059 2.47
S        0     0     0      1.45