Heulandite-Na
Gunter M E, Armbruster T, Kohler T, Knowles C R
American Mineralogist 79 (1994) 675-682
Crystal structure and optical properties of Na- and Pb-exchanged
heulandite-group zeolites
Sample: Na-exchanged
Atomic parameters from ICSD
17.767 17.977 7.422 90 116.14 90 C2/m
atom     x     y     z  occ  Biso
Na1  .1726     0  .689  .80  10.3
Na2  .5392     0  .243  .84   7.3
Na3  .2839     0  .029  .16  16.1
Si1  .1788 .1698 .0958 .753  1.49
Al1  .1788 .1698 .0958 .247  1.49
Si2  .2864 .0892 .4949 .753  1.53
Al2  .2864 .0892 .4949 .247  1.53
Si3  .2905 .3098 .2826 .753  1.52
Al3  .2905 .3098 .2826 .247  1.52
Si4  .0673 .2978 .4171 .753  1.52
Al4  .0673 .2978 .4171 .247  1.52
Si5      0 .2165     0 .753   1.6
Al5      0 .2165     0 .247   1.6
O1   .3026     0  .537        2.4
O2   .2341 .1197 .6182       3.23
O3   .1879 .1556  .891         4.
O4   .2311 .1033 .2498       2.79
O5       0 .3218    .5        3.8
O6   .0807 .1609 .0493       2.83
O7   .3737 .2686 .4492       3.37
O8   .0145 .2709 .1862        3.4
O9   .2123 .2521 .1875       2.93
O10  .1199 .3719 .4212       2.99
OH11 .2839     0  .029  .68  16.1
OH12    .5     0    .5       13.6
OH13  .422 .0814  .035       13.1
OH14  .074     0   .04  .56  26.9
OH15  .082     0  .271       25.4
OH16  .072 -.029  .758  .37 11.84
O17      0    .1    .5       22.2