Database of Disordered Zeolite Structures
 
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  
 
 
  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).

 
  CHA
 
Cell Parameters: trigonal R -3 m (# 166)
    a = 13.6750 Å b = 13.6750 Å c = 14.7670 Å  
  α = 90.0000° β = 90.0000° γ = 120.0000°  
Ring sizes (# T-atoms): 8 6 4  
Channel dimensionality: Topological (pore opening > 6-ring): 3-dimensional  
Channel system: [001] 8 3.8 x 3.8*** (variable due to considerable flexibility of framework)  
 
ABC-6 stacking sequence:  AABBCC
In this space group and setting, the PerBUs are stacked along [001]


Note: This polymorph corresponds to the ordered framework CHA
 
 
  GME
 
Cell Parameters: hexagonal P 63/m m c (# 194)
    a = 13.7500 Å b = 13.7500 Å c = 10.0500 Å  
  α = 90.0000° β = 90.0000° γ = 120.0000°  
Ring sizes (# T-atoms): 12 8 6 4  
Channel dimensionality: Topological (pore opening > 6-ring): 0-dimensional  
Channel system: [001] 12 7.0 x 7.0* <-> [001] 8 3.6 x 3.9**  
 
ABC-6 stacking sequence:  AABB
In this space group and setting, the PerBUs are stacked along [001]


Note: This polymorph corresponds to the ordered framework GME