Intergrowth Family CHA-GME

Periodic Building Unit


Periodic Building Unit (PerBU):	ABC-6 layer of hexagonally arranged (isolated) 6-rings

Layer symmetry	P (6) m m

2D cell parameters	a = 13.05 Å	b = 13.05 Å	gamma = 120°

References
	Millward, G. R., Ramdas, S. and Thomas, J. M.
		"On the direct imaging of offretite, cancrinite, chabasite and other related ABC-6 zeolites and their intergfrowths"
		Proc. R. Soc. Lond., A 399, 57-71 (1985)

Connectivity pattern

Examples

The layers are stacked along the [001] direction using the following connectivity patterns

Symmetry Operation^*	Translation^*	Comment	Image
		Overview showing the A, B and C positions of the ABC-6 layer
	0	A layer
	1/3a, 2/3b	B layer
	2/3a, 1/3b	C layer

^* relative to the first layer


Effect on channel system
	The disorder blocks the 1-dimensional 12-ring channel of gmelinite.

Simplest ordered end members

The color of each layer reflects the translation used to generate it from the first layer (see table above).

-->

	Ring sizes (# T-atoms):	8 6 4
	Channel dimensionality:	Topological (pore opening > 6-ring): 3-dimensional
	ABC-6 sequence:	AABBCC sequence of ABC-6 layers

Composite Building Units:

In this space group and setting, the PerBUs are stacked along [001]

	Note: This polymorph corresponds to the ordered framework CHA

-->

	Ring sizes (# T-atoms):	12 8 6 4
	Channel dimensionality:	Topological (pore opening > 6-ring): 3-dimensional
	ABC-6 sequence:	AABB sequence of ABC-6 layers

Composite Building Units:

In this space group and setting, the PerBUs are stacked along [001]

	Note: This polymorph corresponds to the ordered framework GME

Disorder Example



	The 12-ring channel of GME is blocked by the CHA polymorph