The positions of the double crankshaft chains have been highlighted to facilitate the understanding of the relationships shown in the connectivity pattern table below
References
Lobo, R.F., Tsapatsis, M., Freyhardt, C.C., Chan, I., Chen, C.-Y., Zones, S.I. and Davis, M.E.
"A model for the structure of the large-pore zeolite SSZ-31"
J. Am. Chem. Soc., 119, 3732-3744 (1997)
van Koningsveld, H. and Lobo, R.F.
"Disorder in zeolite SSZ-31 described on the basis of one-dimensional building units"
J. Phys. Chem. B, 107, 10983-10989 (2003)
Connectivity pattern
Examples
The layers are stacked along the [001] direction using the following connectivity patterns
Symmetry Operation*
Translation*
Comment
Image
+2/6 a
+1/6 a
-1/6 a
This is equivalent to +5/6 a or +2/6 a + 1/2 b$
-2/6 a
This is equivalent to +4/6 a or +1/6 a + 1/2 b$
* relative to the previous layer
$ This equivlancy arises from the fact that the double crankshaft chains are at different positions along b
Note: It would also be possible to translate the layer by 0/6 a or 3/6 a, but this would result in a sequence of 6-6-4-rings in the connecting plane instead of the sequence of 6-5-5 rings seen in the ac-projections above. As this 6-6-4-ring sequence has not yet been observed, it is not included here.
Effect on channel system
The disorder does not block the 1-dimensional channel system
Simplest ordered end members
The color of each layer reflects the symmetry/translation operation used to generate it from the previous layer (see table above).
