Cordierite
Gibbs G V
American Mineralogist 51 (1966) 1068-1087
The polymorphism of cordierite I: The crystal structure of low cordierite
_database_code_amcsd 0000149
17.083 9.738 9.335 90 90 90 Cccm
atom      x      y     z occ Biso
Al1     1/4    1/4   1/4      .22
Si2       0    1/2   1/4 .92  .20
Al2       0    1/2   1/4 .08  .20
Si3   .1923  .0781     0      .26
Si4   .1351 -.2372     0      .23
Al5   .0506  .3084     0 .96  .25
Si5   .0506  .3084     0 .04  .25
Mg    .3374      0   1/4 .77  .23
Fe    .3374      0   1/4 .23  .23
O1    .2466 -.1040 .3591      .27
O2    .0616 -.4167 .3494      .24
O3   -.1730 -.3091 .3583      .31
O4    .0434 -.2453     0      .25
O5    .1224  .1848     0      .65
O6    .1639 -.0788     0      .54
Wat       0      0   1/4 .48 7.13
Li        0      0   1/4 .12 7.13
Na        0      0   1/4 .10 7.13
Ca        0      0   1/4 .03 7.13
K         0      0   1/4 .02 7.13