Intergrowth Family CAS-NSI

1-dimensional stacking disorder

Periodic Building Unit


Periodic Building Unit (PerBU):	CAS layer

Layer symmetry	P 1 2/m (1)

2D cell parameters	a = 14.13 Å	b = 5.26 Å	gamma = 90°

References
	B. Marler, M.A. Camblor, H. Gies
		"The disordered structure of silica zeolite EU-20b, obtained by topotactic condensation of the piperazinium containing layer silicate EU-19"
		Microporous Mesoporous Mater., 90, 87–101 (2006)

Connectivity pattern

Examples

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

Symmetry Operation^*	Translation^*	Comment	Image
i	none	one inversion center shown as an open circle in the example
m	none	mirror plane shown as a solid line in the example

^* relative to the previous layer


Effect on channel system
	The disorder does not block the 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).


Polymorph CAS

Cell Parameters:	orthorhombic	C m c m: (# 63)
	a = 5.2560 Å	b = 14.1320 Å	c = 17.2270 Å
	α = 90.000°	β = 90.000°	γ = 90.000°
	Volume =	1279.6 Å³
Framework Density (FD_Si):	18.8

	Ring sizes (# T-atoms):	8 6 5
	Channel dimensionality:	Topological (pore opening > 6-ring): 1-dimensional

Maximum diameter of a sphere:
	that can be included	5.05 Å
	that can diffuse along	a: 2.97 Å	b: 2.21 Å	c: 2.45 Å
		additional volume data

Composite Building Units:


	cas	bik

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 CAS


Polymorph NSI

Cell Parameters:	monoclinic	C 1 2/m 1: (# 12)
	a = 14.1287 Å	b = 5.2535 Å	c = 8.9277 Å
	α = 90.000°	β = 105.370°	γ = 90.000°
	Volume =	639.0 Å³
Framework Density (FD_Si):	18.8

	Ring sizes (# T-atoms):	8 6 5
	Channel dimensionality:	Topological (pore opening > 6-ring): 1-dimensional

Maximum diameter of a sphere:
	that can be included	4.16 Å
	that can diffuse along	a: 2.6 Å	b: 3.3 Å	c: 2.45 Å
		additional volume data

Composite Building Units:


	cas	bik

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 NSI

Disorder Example



	Simple example of a random stacking of CAS and NSI polymorphs.

	There is no blocking of the 1D channel system.