Nikischerite
Huminicki D M C, Hawthorne F C
The Canadian Mineralogist 41 (2003) 79-82
The crystal structure of nikischerite, NaFeAl3(SO4)2(OH)18(H2O)12,
a mineral of the shigaite group
_database_code_amcsd 0005826
9.347 9.347 33.000 90 90 120 R-3
atom      x     y      z Uiso U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3)
Fe   -.0007 .3341 .16683 .022   .020   .020   .024   .010   .001   .001
Al1       0     0  .1651 .026   .017   .017   .042   .009      0      0
Al2     1/3   2/3    1/6 .020   .023   .023   .015   .012      0      0
Na        0     0      0 .050   .052   .052   .046   .026      0      0
S       2/3   1/3  .0383 .034   .034   .034   .035   .017      0      0
O1      1/3   2/3  .0069 .038   .057   .057   .001   .026      0      0
O2     .603  .160  .0543 .049   .084   .021   .031   .019   .004   .001
OH1    .565  .132  .1379 .021   .024   .018   .019   .008  -.014  -.003
OH2    .203  .101  .1351 .025   .024   .036   .023   .022  -.004   .001
OH3    .231  .467  .1357 .023   .025   .014   .035   .015   .001  -.003
Wat1   .127  .425  .0564 .056   .052   .052   .071   .032   .005   .013
Wat2   .212  .178  .0505 .059   .045   .051   .067   .014   .007   .011