SSZ-70: DO Family

Intergrowth Family SSZ-70

Periodic Building Unit


Periodic Building Unit (PerBU):	MWW layer

Layer symmetry	P (6) m m

2D cell parameters	a = 14.23 Å	b = 14.23 Å	gamma = 120°

References
	Smeets, S., Berkson, Z.J., Xie, D., Zones, S.I., Wan, W., Zou, X., Hsieh M.-F., Chmelka, B.F., McCusker, L.B. and Baerlocher, Ch.
		"Well-defined silanols in the structure of the calcined high-silica zeolite SSZ-70: new understanding of a successful catalytic material"
		J. Am. Chem. Soc., 139, 16803-16812 (2017)

Connectivity pattern

Examples

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

Symmetry Operation^*	Translation^*	Comment	Image
	2/3 a, 1/3b	The 3-connected T Atoms on the layer surfaces are only half occupied
	1/3 a, 2/3b	The 3-connected T Atoms on the layer surfaces are only half occupied
m	None

^* relative to the previous layer


Effect on channel system
	The disorder partly blocks the channel system between the layers, but not the one within the layer

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).


Polymorph SSZ-70_A

Cell Parameters:	hexagonal	P 6₃/m m c: (# 194)
	a = 14.2270 Å	b = 14.2270 Å	c = 49.8060 Å
	α = 90.0000°	β = 90.0000°	γ = 120.0000°
	Volume =	8730.1 Å³
Framework Density (FD_Si):	16.3

	Ring sizes (# T-atoms):	14 10 6 5 4
	Channel dimensionality:	Topological (pore opening > 6-ring): 2-dimensional

Maximum diameter of a sphere:
	that can be included	7.86 Å
	that can diffuse along	a: 4.71 Å	b: 4.71 Å	c: 2.58 Å
		[1 0 0] : 4.71 Å
		addional volume data

Composite Building Units:


	d6r		mel

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

	Note: This polymorph has NOT been observed as a pure ordered material


Polymorph SSZ-70_B

Cell Parameters:	hexagonal	R -3 m:H (# 166)
	a = 14.3962 Å	b = 14.3962 Å	c = 75.5875 Å
	α = 90.0000°	β = 90.0000°	γ = 120.0000°
	Volume =	13566.8 Å³
Framework Density (FD_Si):	15.7

	Ring sizes (# T-atoms):	14 10 6 5 4
	Channel dimensionality:	Topological (pore opening > 6-ring): 2-dimensional

Maximum diameter of a sphere:
	that can be included	8.43 Å
	that can diffuse along	a: 4.93 Å	b: 4.93 Å	c: 2.54 Å
		[1 0 0] : 4.93 Å
		addional volume data

Composite Building Units:


	d6r		mel

In this space group and setting, the PerBUs are stacked along [001]
Adjacent layers generated by the same connectivity pattern (same basic color) are shown with different shades for clarity.

	Note: This polymorph has NOT been observed as a pure ordered material


Polymorph SSZ-70_C

Cell Parameters:	hexagonal	P 6/m m m: (# 191)
	a = 14.3900 Å	b = 14.3900 Å	c = 25.1980 Å
	α = 90.000°	β = 90.000°	γ = 120.000°
	Volume =	4518.8 Å³
Framework Density (FD_Si):	15.9

	Ring sizes (# T-atoms):	10 6 5 4
	Channel dimensionality:	Topological (pore opening > 6-ring): 2-dimensional

Maximum diameter of a sphere:
	that can be included	9.69 Å
	that can diffuse along	a: 4.92 Å	b: 4.92 Å	c: 2.6 Å
		addional volume data

Composite Building Units:


	d6r		mel

In this space group and setting, the PerBUs are stacked along [001]
Adjacent layers generated by the same connectivity pattern (same basic color) are shown with different shades for clarity

	Note: This polymorph corresponds to the ordered framework MWW

Disorder Example



	There is no blocking of the 2D channel system.